To strike with something flat or heavy; to bang, or thrash: to thump.

A heavy blow with something flat or heavy; a thump.

a hard blow with a flat object

1) The sound the fly makes when it rebounds off an obstruction during the cast (Not Good). 2) The sound a fly makes when rebounds off you during the cast (Worse, but better than Scrish, which is the sound the fly makes as it imbeds in some body part or other- See First Aid Kit).

To fill to overflow.