clubmossPronunciation: /ˈklʌbmɒs/Definition of clubmoss noun a low-growing flowerless plant that resembles a large moss, having branching stems with undivided leaves. Class Lycopsida, division Pteridophyta: three living families, in particular Lycopodiaceae and Selaginellaceae (the lesser clubmosses) clubmoss in other Oxford dictionaries Definition of clubmoss in the US English dictionary