Definition of "Fast" :

noun: abstaining from food

verb: abstain from eating

"Before the medical exam, you must fast."

verb: abstain from certain foods, as for religious or medical reasons

"Catholics sometimes fast during Lent."

adjective: (of a photographic lens or emulsion) causing a shortening of exposure time

"A fast lens."

adjective: unwavering in devotion to friend or vow or cause

"Fast friends."

adjective: acting or moving or capable of acting or moving quickly

"Fast film."

adjective: at a rapid tempo

"The band played a fast fox trot."

adjective: (used of timepieces) indicating a time ahead of or later than the correct time

"My watch is fast."

adjective: securely fixed in place

adjective: hurried and brief

"A fast visit."

adjective: unrestrained by convention or morality

"Fast women."

adjective: resistant to destruction or fading

"Fast colors."

adjective: (of surfaces) conducive to rapid speeds

"A fast road."

adverb: quickly or rapidly (often used as a combining form)

"How fast can he get here?."

adverb: firmly or closely

"Held fast to the rope."