Pronunciation: (tru-bek'yu-lu),[key] —n., —pl.-laePronunciation: (-lē").[key] 1. Anat.,Bot.a structural part resembling a small beam or crossbar.
2. Bot.one of the projections from the cell wall that extends across the cavity of the ducts of certain plants, or the plate of cells across the cavity of the sporangium of a moss.