-tre·ma \.ˈtrēmə\noun combining form Etymology: New Latin -tremat-, -trema, from Greek trēmat-, trēma hole — more at throw 1.plural-tremas\-məz\or-trema·ta\-məd.ə, -mətə\: hole : orifice : opening < helicotrema > 2.: creature having (such) an opening — in generic names < Eurytrema >