If your handwriting is illegible, then you can not understand what word is written.
But if you have not drawn well then you can not understand what is being drawn.
What word do I use for this?
Edit: The objects being drawn here are TV, cars, clocks, etc. The drawing of the TV does not look like a TV
I would say the drawing is unrecognizable:
un·rec·og·niz·a·ble (adjective) — not able to be recognized or identified.
You might say that the drawing is "indecipherable", which is defined by Merriam-Webster as "impossible to read or understand : not decipherable".
I would go for inscrutable. There are many words that do the trick, and a lot of good answers, but I think inscrutable works particularly well. In fact, the first example in Webster's definition refers specifically to art!
inscrutable
adjective
\in-ˈskrü-tə-bəl\
not readily investigated, interpreted, or understood
an inscrutable work of art
Source: Merriam-Webster.com
Oxford dictionary has this to say:
"inscrutable. impossible to understand or interpret"
Oxford dictionary, Mac edition
Or, perhaps, unintelligible, which works for representational art and might also work if one were referring to non-representational art.
I would personally go for
Incomprehensible
Adjective, not able to be understood; not intelligible.
I would say it's indiscernible or unintelligible.
Other suggestions have unwanted connotations, like:
PS:
Actually unintelligible also might be, maybe, fitting to the wrong-connotation category. So the main suggestion would be indiscernible.
PPS:
Maybe just ugly?
I think the best solution to this SWR is indeed simply
Note that, of course and obviously, the OP means ordinary representational ("non artistic", let's say) drawings.
Imagine, say, a board game where you have to draw an object (cat, dog, car, house - whatever) and the other players have to guess what it is. Or, the line drawings of objects in small children's books. Or playing Scribblenauts.
I feel in that situation, you'd say things like "It's unclear what you've drawn!" "I have no idea what that drawing is!" "What the heck were you trying to draw here?"
That milieu is the most analogous in the question as actually put, "Handwriting is to illegible as drawing is to what?"
Really, "unclear" is the only word that works there, I think.
If, as many folks have commented, the OP meant Jackson Pollock paintings, the whole question is vague and should be deleted. The question ("Handwriting is to illegible as drawing is to what?") is only meaningful if you're talking about "drawings" in the sense of straightforward line drawings of things.
Unrecognisable is wrong because it usually means, that the visual process by which you are viewing some thing (perhaps a person, car, drawing, animal, house - or any thing) is of low quality such that you cannot recognise what the thing is. This is utterly unrelated to the drawing being so "bad" that it is not clear which object is being suggested (ie - "unclear").
indecipherable applies more to "reading' (see the dictionary definition; note "ciphers". if the word was more like "in-line-able" it would be suitable here.)
unintelligible means impossible to understand. it only makes sense when a meaning is attempting to be communicated. So, a sentence can be unintelligible. in contrast a single character (like "d") is not trying to communicate a message, it's a single symbol - which may be unclear
Illegible is, in fact, often used.
Drawings are read like texts (especially by Art Historians). For this context, the drawing is attempting to participate in a narrative ("it's a car!"), and failing, out of incompetence.
The drawing is supposed to be a noun, but it's not: it's illegible.
Scribble seems the most descriptive word for a bad or unrecognizable drawing.
Your drawing is confusing
Simple, yes?
“Hieroglyphic/hieroglyphical”:
adj
1 …; 2 … ; 3 difficult to read or decipher.
noun 4 …; 5 a symbol or picture that is difficult to read or decipher.
(from English Collins Dictionary via Reverso/net)
(Granted however, it seems to work for both writing and drawing, making “Handwriting is to hieroglyphic/al as drawing is to hieroglyphic/al” yet another one of my pointless observations.)
Uninterpretable
Everyone interprets art differently. If the art was to be "illegible", it could not be interpreted.
For a drawing, the word inappreciable might be suited.
The drawing he made was unfathomable
adjective 1. not able to be fathomed, or completely understood; incomprehensible:
inaccessible is another word specifically used for art (as opposed to, say, a drawing of a roadsign or something literal). "(Of language or an artistic work) difficult to understand or appreciate."
Along with the usual unrecognizable, indiscernible, unintelligible which people have cited.
I voted for unrecognizable, but I wanted to add a simpler wording:
The drawing is bad.
This is badly drawn.
The drawing is crap. (from RemarkLima's comment)
Substitute draw with paint or another art method as needed. Note that this only works if it's hard to recognize because it's badly drawn. A photograph of an exploding egg might be hard to recognize while being perfectly accurate.
Something to point out here, is that there isn't actually a direct correlation between drawing and writing here. Writing uses a set of very standardized symbols that have very specific meanings, and those symbols are arranged in very specific ways with very specific syntax. Certainly, there's a great deal of allowable variation in writing, but it follows the rules.
With drawing, it's always abstract. How one person perceives a television can be very different from how another person perceives it. With a highly detailed attempt at photo-realism, it's likely most humans will tend to converge on a very similar representation (given enough skill of course) because we basically see a bitmap, and are capable of conveying data in that form.
But if we're talking about relatively simple drawings, we internally caricaturize external objects based on the aspects we consider important. To one artist who grew up in the 70s to 80s, a television could be characterized by things like the channel and volume knobs, and being shaped like a big box. To someone who's growing up now, a television could be more akin to a painting hung on the wall. And our drawings will reflect those differences.
But, because drawings are things we tend to share with, and learn from, others, we will tend to standardize them implicitly. So people who grew up together might tend to draw one aspect of something and to the people around them it's quite obvious what they drew, while an outsider might just see ink on a page. As an example, look at the differences between American and Japanese emoticons. The American icons tend to focus on the mouth, while the Japanese icons focus on the eyes. If I didn't know it was on a chart of emoticons, I wouldn't even see that (^3^) was supposed to be a face.
When we talk about illegible writing, we mean we can't figure out what basic symbols are on the page. When we talk about "illegible" drawings, we often are talking about a totally different "language" of art that we just don't know the rules to.
