Synonyms for Crowded:

adj.

busy, congested (adjective)
packed, thronged, jam-packed, thick, close, full, dense, swarming, tight, cramped, compact, crushed, jammed, teeming, huddled.
dense (adjective)
thick.
littered (adjective)
cluttered.
narrow (adjective)
cramped.
numerous (adjective)
legion, numerous, ample, many, countless, multitudinous, plenty, swarming, bounteous, Thronging, abundant.
populous (adjective)
thronged.

n.

teeming, bulging. narrow, tight, tighten, cramped, close, confining, snug. dense, thick, compact. cluttered, simple, busy, fussy. crowded (noun)
jam-packed, packed, thronged, huddled, jammed.
packed (noun)
crushed, thick, congested, full.

Other synonyms:

cluttered, teeming, bulging, congested. dense, compact. fussy, confining. narrow, busy. snug. tight, close. filled
full.
Other relevant words:
busy, packed, dense, snug, cluttered, huddled, compact, tight, jam-packed, close, narrow, bulging, thick, tighten, fussy, thronged, cramped, jammed, crushed, full, teeming, simple, congested, confining.

Usage examples for crowded

  1. We're crowded as we are now with only three hundred odd. – “Crumps”, The Plain Story of a Canadian Who Went by Louis Keene
  2. Presently they were in the dining- room, already crowded – Back To Billabong by Mary Grant Bruce
  3. The cabin was already crowded – The Portal of Dreams by Charles Neville Buck