WordWeb Online

1. (often followed by 'of') a large number, amount or extent
   "a hatful of letters";
   - batch, deal, flock, good deal, great deal, heap, lot, mass, mess, mickle [archaic], mint, mountain, muckle, passel [US], peck, pile [informal], plenty, pot, quite a little, raft, sight, slew, spate, stack, tidy sum, wad, bunch [informal]
    
2. As many or as much as a hat will hold

Derived forms: hatfuls

Type of: containerful, large indefinite amount, large indefinite quantity