dumbfound
Cross references: 1. puzzle dumb.found or dum.found \d*m-'fau.nd\ vt [dumb + -found (as in confound)] : to strike dumb with astonishment
Cross references: 1. puzzle dumb.found or dum.found \d*m-'fau.nd\ vt [dumb + -found (as in confound)] : to strike dumb with astonishment