'ad-lib' definitions:

Definition of 'ad-lib'

From: WordNet
adjective
With little or no preparation or forethought; "his ad-lib comments showed poor judgment"; "an extemporaneous piano recital"; "an extemporary lecture"; "an extempore skit"; "an impromptu speech"; "offhand excuses"; "trying to sound offhanded and reassuring"; "an off-the-cuff toast"; "a few unrehearsed comments" [syn: ad-lib, extemporaneous, extemporary, extempore, impromptu, offhand, offhanded, off-the-cuff, unrehearsed]
adjective
Said or done without having been planned or written in advance; "he made a few ad-lib remarks" [syn: ad-lib, spontaneous, unwritten]
noun
Remark made spontaneously without prior preparation; "his ad-libs got him in trouble with the politicians"
verb
Perform without preparation; "he extemporized a speech at the wedding" [syn: improvise, improvize, ad-lib, extemporize, extemporise]