gesas noun English. Heart of forest trees which remains when outer portion has rotted away. Example sentence: Subanen. Lema' mekpabang pau dini'a, engain ta su gesas nilu' tug binaalan ni Sibiu. English. Tomorrow I'll ask your help, and we'll go get the heartwood of the nilu' tree in Sebio's rice field. Example sentence: Subanen. Ki gayu gesusu' penega'en, dayun sa' medepet na lima taun buat penega'ay su bukalen mbaluy dayun gesas. English. Fell a gesusu' tree, then when five years have passed since the felling, the heartwood becomes a hard core. verb English. Of a tree, becomes heartwood, loses its softer outer wood, matures. Synonym. lela Generic. bukal