Origin of the word "sketchy"

Question

The definition of the Informal word "Sketchy" is as follows:

Sketchy [skech-ee]

Adjective Informal.

1. unreliable or unsafe:

That street looks pretty sketchy.

2. disreputable or shady:

I'd stay away from him; he's got a sketchy past.

What is the Origin of this Usage? How does it relate to the word Sketch?

Sketch [skech]

Noun

1. a simply or hastily executed drawing or painting, especially a preliminary one, giving the essential features without the details.

2. a brief or hasty outline of facts, occurrences, etc.:

a sketch of his life.

3.a short, usually descriptive, essay, history, or story.

4.a short play or slight dramatic performance, as one forming part of a vaudeville program.

Etymonline only has the Origin of the Formal "Sketchy" describing an unfinished work.

Answer 1

According to the Language Log sketchy meaning disreputable, shady may originate from a figurative extension of it original meaning and its assonance with terms like scummy, scurvy etc:

• My assumption (without real evidence) is that that this usage started with the sense "composed of an outline without much detail" (OED sense 2), and the figurative extension "Of a light, flimsy, unsubstantial or imperfect nature" (OED sense 3), further extended via the phonetic associations of neighbor-words like scummy, scurvy, scruffy, scuzzy,skeevy.

• This usage has come up in a few LL posts over the years (e.g. "Sketchballs", 2/18/2006; "Skeevy", 6/22/2009), but we've never tried to track its origin and progress in time and space. It's not easy to do this, because even today, the great majority of uses of sketchy are the more traditional senses.

• One way past this problem is to look for particular collocations (like "sketchy guy(s)") that are highly likely to involve the new sense. Tracking this phrase in Google books, we find this from the teen novel Brave New Girl (2001):

  • He looks like a crazy person, like some sketchy guy you'd see on TV. Actually, more like some stupid actor playing some sketchy guy — too good-looking to actually be sketchy.

Answer 2

Merriam-Webster's Eleventh Collegiate Dictionary (2003) offers three definitions for sketchy:

sketchy adj (1805) 1 : of the nature of sketch : roughly outlined 2 : wanting in completeness, clearness, or or substance : SLIGHT, SUPERFICIAL {the detail are sketchy} 3 : QUESTIONABLE, IFFY {got into a sketchy situation} {a sketchy character}

The sense of "iffy, questionable, ambiguous, or not yet settled" implicit in definition 3 above seems to have morphed at some point into the sense of "unstable, unreliable, or dangerous." To me, the shift seems not especially surprising—just as the shift from "roughly drawn or outlined" to "incomplete or not filled in" and thence to "questionable, iffy" follows an intuitive progression.

A Google Books search turns up several matches for "sketchy neighborhood" and "sketchy area" from the 1990s. From The Princeton Review Student Access Guide to America's Top 100 Internships (1993):

Quality of Life

Creative environment

Workshops and Evert lectures; Sketchy neighborhood

From Elisabeth Scribner, Italy '96: On the Loose, On the Cheap, Off the Beaten Path (1995):

The main drawback is the sketchy neighborhood; women might not want to wander around alone at night.

From Jeff Brauer, ‎Julian Smith & ‎Veronica Wiles, On Your Own in El Salvador (1995):

Mail: The central post office is in a sketchy area just north of the Centro Gobierno, east of the Parque Infantfl and the Palacio de los Deportes.

From The Right to Live Without Violence: Women's Proposals and Action (1996):

The explanation, apparently, is that when a girl is raped on the corner of some sketchy neighborhood, she tends to say, "I'll never go back to that place, I'll just stay home." But if she is raped at work or in her house, she has no safe place left where she can seek refuge, where she can escape.

From Central America: On the Loose, on the Cheap, Off the Beaten Path (1996):

This is a sketchy area—take a taxi.

From Shaheena Ahmad, The Yale Daily News Guide to Succeeding in College (1997):

It's also not a good idea to take a job too far from campus; you don't want to be paying an arm and a leg in transportation costs or losing an arm or a leg after walking home from work through a sketchy neighborhood.

From Frommer's San Francisco from $60 a Day (1997):

The only drawback is the sketchy neighborhood, where there's a lot of hustling for change going on, but that's life in the Haight.

It thus appears that sketchy in the sense of "unsafe" was in use in the United States by 1993 and proliferated during the mid-1990s.