The Varied Meanings of Sketchy

A sketch is a rough drawing usually done as an initial draft in contrast to a finished work. The word sketch suggests imperfection and a lack of refinement. It comes from the Dutch word schets and ultimately from the Italian verb schizzare, an imitative verb meaning "to splash."

Unsurprisingly, the adjective sketchy originally described something relating to or resembling a sketch, as in "a sketchy portrait." But because sketches are by nature rough and ill-defined, sketchy soon came to mean "wanting in completeness, clearness, or substance," as in "a sketchy understanding" or "sketchy details."

What lacks completeness, clearness, or substance is also subject to doubt or challenge, and sketchy went on to develop uses applying to what is questionable or iffy, either for physically obvious qualities or for something less tangible. In sports we see this sense of sketchy applied to a track or surface that is poorly maintained, as in "a sketchy track," and in broader use it is applied to streets and neighborhoods that can also be described as seedy, as in "a sketchy part of town."

The adjective has more recently extended in use to describe someone who creates an impression of unsavoriness, or something that comes from an untrustworthy source or is itself untrustworthy, as in "a sketchy dude" or "a scheme that sounds sketchy."