CAUSTIC, CAUSTICAL, adjective Burning; corroding; destroying the texture of animal flesh. CAUSTIC, noun In medicine, any substance which applied to living animals, acts like fire, in corroding the part and dissolving its texture; an escharotic. [See Causticity.] Lunar caustic a preparation of crystals of silver, obtained by solution in nitric acid, and afterwards fused in a crucible. It is a nitrate of silver. CAUSTIC curve, in geometry, a curve formed by a coincidence of rays of light reflected from another curve.
Source: Webster's 1828 American Dictionary ↗ · public-domain · returned verbatim, no AI