| Noun | 1. | tidy sum - (often followed by `of') a large number or amount or extent; "a batch of letters"; "a deal of trouble"; "a lot of money"; "he made a mint on the stock market"; "see the rest of the winners in our huge passel of photos"; "it must have cost plenty"; "a slew of journalists"; "a wad of money"good deal, great deal, hatful, lot, muckle, passel, peck, mickle, mint, quite a little, slew, spate, stack, wad, raft, mountain, pile, plenty, mass, batch, heap, deal, flock, pot, mess, sight large indefinite amount, large indefinite quantity - an indefinite quantity that is above the average in size or magnitude deluge, flood, inundation, torrent - an overwhelming number or amount; "a flood of requests"; "a torrent of abuse" haymow - a mass of hay piled up in a barn for preservation |