The Collaborative International Dictionary of English v.0.48:

Overload \O`ver*load"\, v. t. [imp. & p. p. Overloaded; p. pr.
   & vb. n. Overloading.] [Cf. Overlade.]
   To load or fill to excess; to load too heavily.
   [1913 Webster]

WordNet (r) 3.0 (2006):

overloaded
    adj 1: loaded past capacity [syn: overladen, overloaded]

Moby Thesaurus II by Grady Ward, 1.0:

73 Moby Thesaurus words for "overloaded":
   adorned, befrilled, bloated, burdened, bursting, charged, choked,
   colored, congested, crammed, crowded, cumbered, decorated,
   distended, drenched, embellished, embroidered, encumbered, fancy,
   festooned, figurative, figured, filled to overflowing, florid,
   flowery, fraught, freighted, glutted, gorged, hampered, hyperemic,
   in spate, jam-packed, jammed, laden, loaded, lush, luxuriant,
   oppressed, ornate, overblown, overburdened, overcharged, overfed,
   overflowing, overfraught, overfreighted, overfull, overladen,
   overstocked, overstuffed, oversupplied, overtaxed, overweighted,
   packed, plethoric, purple, ready to burst, running over, saddled,
   satiated, saturated, soaked, stuffed, stuffed up, supercharged,
   supersaturated, surcharged, surfeited, swollen, taxed, weighted,
   weighted down