octuple UK /ɒkˈtuː.pəl/US /ˈɑk.t(j)u.pəl/verb 2adjective 1noun 1forms 3 verb2 •To increase eightfold. •To increase or multiply something by eight. adjective1 •eightfold noun1 •An eightfold amount or number formsoctupled · octupling · octuples