Answer:

fast

Answer	Crossword Clue
FAST	Breakneck ... or something to break
FAST	Observe Ramadan
FAST	Observance on Yom Kippur or during Ramadan

FAST	Fleet
FAST	Not eat
FAST	Presto
FAST	Ramadan observance
FAST	Speedy
FAST	Express
FAST	Eschew one's food?
FAST	... and 61-Across (one way to play)

FAST	Unfading
FAST	Partner of hard
FAST	Lickety-split
FAST	Quick
FAST	Firmly fixed
FAST	Like some friends
FAST	Have no input?
FAST	Cut off all intake

FAST	How a painkiller should act
FAST	Secured
FAST	Firmly secured
FAST	Observe Yom Kippur
FAST	Like some tracks and talkers
FAST	Certain protest
FAST	Take nothing in
FAST	Prisoner's protest

FAST	Yom Kippur ritual
FAST	Securely
FAST	Ultimate diet
FAST	Sexually unrestrained
FAST	Lent activity
FAST	On the double
FAST	Crash diet
FAST	Firm

FAST	Accelerated
FAST	Eschew food
FAST	Eat not
FAST	Opposite of gormandize