Definitions of ad-lib:
- noun: remark made spontaneously without prior preparation
Example: "His ad-libs got him in trouble with the politicians"
- verb: perform without preparation
- adjective: with little or no preparation or forethought
Example: "His ad-lib comments showed poor judgment"
- adjective: said or done without having been planned or written in advance
Example: "He made a few ad-lib remarks"