- Bradley doesn't know diddly about running his own business.
diddlydid‧dly /ˈdɪdli/ (also did‧dly‧squat /ˌdɪdliˈskwɒt $ ˈdɪdliskwɑːt/) American English informal noun 
not know/mean diddly to know or mean nothing at all: 
Brad? He doesn’t know diddly about baseball.
not know/mean diddly to know or mean nothing at all: Brad? He doesn’t know diddly about baseball.