firs is a form of:

Fir



noun
1.
(a kind of evergreen conebearing tree of the pine family, its wood, coniferous tree) ដើមស្ងាវ, ដើមស្រល់, ឈើស្រល់
ENGLISH MEANING
noun
1.
A genus (Abies) of coniferous trees, often of large size and elegant shape, some of them valued for their timber and others for their resin. The species are distinguished as the balsam fir, the silver fir, the red fir, etc. The Scotch fir is a Pinus.