(1):

(n.) The catch in a gunlock by which the hammer is held cocked or half cocked.

(2):

(a.) To burn (the surface of) to dryness and hardness; to cauterize; to expose to a degree of heat such as changes the color or the hardness and texture of the surface; to scorch; to make callous; as, to sear the skin or flesh. Also used figuratively.

(3):

(a.) Alt. of Sere

(4):

(a.) To wither; to dry up.