fast

unwavering in devotion to friend or vow or cause

“fast friends”

at a rapid tempo

“the band played a fast fox trot”

causing a shortening of exposure time

“a fast lens”

conducive to rapid speeds

“a fast road”

resistant to destruction or fading

“fast colors”

indicating a time ahead of or later than the correct time

“my watch is fast”

firmly or closely

“held fast to the rope”

securely fixed in place

hurried and brief

“a fast visit”

abstaining from food

unrestrained by convention or morality

“fast women”

abstain from certain foods, as for religious or medical reasons

“Catholics sometimes fast during Lent”