Webster's Revised Unabridged Dictionary · 1913

Labile

Labile , adjective

[Latin labilis apt to slip, from labi to slip.]

1.
Liable to slip, err, fall, or apostatize. [Obsolete] — Cheyne
2.
Liable or likely to change.
3.
(Chemistry) Easily decomposed or inactivated when subjected to heat, radiation, or mildly acidic or alkaline conditions; -- of chemical compounds; as, enzymes from thermophilic organisms are not as labile as those from mesophiles.