One of the minute apertures between the cells in many serous membranes. [1913 Webster]
The minute breathing pores of leaves or other organs opening into the intercellular spaces, and usually bordered by two contractile cells. [1913 Webster]
A stigma. See Stigma, n., 6 (a) & (b). [1913 Webster]
Stoma, n. (pl. stomas or stomata)
1 Bot. a minute pore in the epidermis of a leaf.
2 a Zool. a small mouthlike opening in some lower animals. b Surgery a similar artificial orifice made in the stomach.