πταίειν
From LSJ
γέλως ἄκαιρος κλαυμάτων παραίτιος → ill-timed laughter causes tears (Menander)
Greek > English (Woodhouse Verbs Reversed)
(see also πταίω): stumble, be at fault, be disappointed, be mistaken, be wrong, come to grief, fall over, have a spill, make a false step, make a mistake, make a slip, stumble against