Dictionary definition · fast
noun
- abstaining from food
verb
- abstain from certain foods, as for religious or medical reasons"Catholics sometimes fast during Lent"
- abstain from eating"Before the medical exam, you must fast"
adjective
- acting or moving or capable of acting or moving quickly"fast film"
- (used of timepieces) indicating a time ahead of or later than the correct time"my watch is fast"
- at a rapid tempo"the band played a fast fox trot"
- (of surfaces) conducive to rapid speeds"a fast road"
- resistant to destruction or fading"fast colors"
- unrestrained by convention or morality"Congreve draws a debauched aristocratic society"
- hurried and brief"paid a flying visit"
adverb
- quickly or rapidly (often used as a combining form)"how fast can he get here?"
- firmly or closely"held fast to the rope"
Source: Open English WordNet (CC BY 4.0).