The Collaborative International Dictionary of English v.0.48:

Congested \Con*gest"ed\, a.
   1. (Bot.) Crowded together. --Gray.
      [1913 Webster]

   2. (Med.) Containing an unnatural accumulation of blood;
      hyper[ae]mic; -- said of any part of the body.
      [1913 Webster]

WordNet (r) 3.0 (2006):

congested
    adj 1: overfull as with blood [syn: congested, engorged]

Moby Thesaurus II by Grady Ward, 1.0:

107 Moby Thesaurus words for "congested":
   SRO, bloated, blocked, bound, brimful, brimming, bulging, bursting,
   capacity, chock-full, choked, choked up, chuck-full, clogged,
   clogged up, close, close-knit, close-textured, close-woven,
   compact, compacted, compressed, concentrated, concrete, condensed,
   consolidated, constipated, costive, cram-full, crammed,
   crammed full, crowded, dense, distended, drenched, farci, filled,
   filled to overflowing, firm, flush, foul, fouled, full,
   full to bursting, gluey, glutted, gorged, hard, heavy, hyperemic,
   impenetrable, impermeable, in spate, infarcted, jam-packed, jammed,
   massive, nonporous, obstipated, obstructed, overblown,
   overburdened, overcharged, overfed, overflowing, overfraught,
   overfreighted, overfull, overladen, overloaded, overstocked,
   overstuffed, oversupplied, overweighted, packed,
   packed like sardines, plenary, plethoric, plugged, plugged up,
   ready to burst, replete, round, running over, satiated, saturated,
   serried, soaked, solid, standing room only, stopped, stopped up,
   stuffed, stuffed up, substantial, supercharged, supersaturated,
   surcharged, surfeited, swollen, thick, thick-growing, thickset,
   topful, viscid, viscose, viscous