WordNet (r) 3.0 (2006):

overburdened
    adj 1: heavily burdened with work or cares; "bowed down with
           troubles"; "found himself loaded down with
           responsibilities"; "overburdened social workers";
           "weighed down with cares" [syn: bowed down(p), loaded
           down(p), overburdened, weighed down(p)]

Moby Thesaurus II by Grady Ward, 1.0:

57 Moby Thesaurus words for "overburdened":
   bloated, burdened, bursting, charged, choked, congested, crammed,
   crowded, cumbered, distended, drenched, encumbered,
   filled to overflowing, fraught, freighted, glutted, gorged,
   hampered, hyperemic, in spate, jam-packed, jammed, laden, loaded,
   oppressed, overblown, overcharged, overfed, overflowing,
   overfraught, overfreighted, overfull, overladen, overloaded,
   overstocked, overstuffed, oversupplied, overtaxed, overweighted,
   packed, plethoric, ready to burst, running over, saddled, satiated,
   saturated, soaked, stuffed, stuffed up, supercharged,
   supersaturated, surcharged, surfeited, swollen, taxed, weighted,
   weighted down