(figuratively) Inaccurate; not correct or appropriate. / Making a start (generally in comparison to others).

Alternative form of off-the-shelf.

(colloquial, with regard to income) Undeclared for tax and social insurance etc.

(sports, of an incident or foul) Occurring away from active play.

(of a garment) not covering the shoulders.

Alternative spelling of off the books (preceding a noun only)

Exceeding the normal range of measurement.

Outside of the normal range of measurement; beyond expectations.

Not at work; off duty. / Not being paid for working. / Relaxing.

(idiomatic) Violating rules or decorum; out of bounds. / (US, politics) Having broken with one's party or group, usually temporarily.