stump vb
1 baffle, bewilder, bring (someone) up short, confound, confuse, dumbfound, flummox, foil, mystify, nonplus, outwit, perplex, puzzle, snooker, stop, stymie
2 clomp, clump, lumber, plod, stamp, stomp (informal) trudge
stump up
chip in (informal) come across with (informal) contribute, cough up (informal) donate, fork out (slang) hand over, pay, shell out (informal)