- : Unstable, unsteady, not fixed. In psychology or psychiatry, labile denotes free and uncontrolled moods or behaviors expressing emotions. In biochemistry, labile means easily removable as, for example, a labile hydrogen molecule. In the context of diabetes, labile is a term used when a diabetic person's blood glucose (sugar) level often swings quickly and widely from high to low and from low to high. Also called brittle and unstable diabetes or type I diabetes. Labile comes from the Latin labilis, meaning liable to slip.
* * *Unstable; unsteady, not fixed; denoting: 1. An adaptability to alteration or modification, i.e., relatively easily changed or rearranged. 2. Certain constituents of serum affected by increases in heat. 3. An electrode that is kept moving over the surface during the passage of an electric current. 4. In psychology or psychiatry, denoting free and uncontrolled mood or behavioral expression of the emotions. 5. Easily removable; e.g., a l. hydrogen atom. [L. labilis, liable to slip, fr. labor, pp. lapsus, to slip]
* * *a) readily or continually undergoing chemical, physical, or biological change or breakdown <a \labile antigen>b) characterized by wide fluctuations (as in blood pressure or glucose tolerance) <\labile hypertension> <\labile diabetes>c) emotionally unstable
* * *la·bile (laґbəl) (laґbīl) [L. labilis unstable, from labi to glide] 1. gliding; moving from point to point over the surface; unstable; fluctuating. 2. chemically unstable.
Medical dictionary. 2011.