balsam fir

noun

1. a pale yellow or greenish, slightly fluorescent, clear, viscous, bitter-tasting, water-insoluble liquid, having a pleasant, aromatic, pinelike odor, and solidifying on exposure to air: obtained from the balsam fir, Abies balsamea, and used chiefly for mounting objects on microscope slides, in the manufacture of fine lacquers, and as a cement for lenses.

noun

1. a yellow transparent resin obtained from the balsam fir. Because its refractive index is similar to that of glass, it is used as an adhesive in optical devices and as a mounting medium for microscope specimens
2. another name for balsam fir