Is there a better alternative to ambiguous for a word with a wide range of meanings, difficult to find, because they become different in connection with person's opinion.
Polysemy - "a diversity of meanings"
A word is polysemous if it has a diversity of meanings.
If a word is used in a sentence and the meaning of that word in that sentence is not obvious, I would say the sentence is ambiguous, rather than saying the word is ambiguous. For example, "I overlooked the valley." (Did you look at it, or completely miss noticing it?) or "Man was here first" (Was a man here before a woman, or was mankind here before an animal?)
A word is polysemous if it has multiple meanings, but that often doesn't mean ambiguous -- it is almost always easy to determine the meaning of a word from its context.
is a good single word to describe a word having multiple meanings. 'Polysemous' is the technically correct word but is jargon for linguists.
Other words for indicating that one meaning has not been specified are
but they aren't specifically about multiple meanings.
But one can be direct and just say 'That word has multiple meanings'.
Not a single word, but "open to interpretation" is a phrase that means what you're trying to say.
Another technical term for this is polysemantic, which means having multiple meanings.
Source: http://www.memidex.com/polysemantic (originally from Princeton WordNet). A related noun could be polysemant (same source).
Intelligence is a polysemantic word.