Answer:

rapid

Answer	Crossword Clue
RAPID	Lightning-quick
RAPID	R.E.M. member?
RAPID	Like some transit

RAPID	Fast
RAPID	Fast-moving
RAPID	Expeditious
RAPID	High-speed
RAPID	Fleet
RAPID	Quick
RAPID	Speedy
RAPID	Hasty

RAPID	Swift
RAPID	Like arpeggioed notes
RAPID	.. Robert: nickname for pitcher Bob Feller
RAPID	Part of REM
RAPID	Breakneck
RAPID	Like white water current
RAPID	Word before transit or fire
RAPID	... Deployment Force (one Marine division and four Army divisions)

RAPID	Like a charging cheetah
RAPID	Brisk
RAPID	Hardly leisurely
RAPID	Quite quick
RAPID	Before fire or transmit
RAPID	Canoeing thrill
RAPID	Part of R.E.M.
RAPID	Moving quickly

RAPID	Part of BART
RAPID	Very quick
RAPID	Presto
RAPID	Cursory.
RAPID	Speedy.
RAPID	Swift.
RAPID	Bob Feller's epithet ... Robert.
RAPID	Acting with great speed.

RAPID	Adjective for modern transit.
RAPID	Fast-moving.
RAPID	In less than usual time.
RAPID	Word for some transit.
RAPID	Fleet.