- deep
- O.E. deop, from P.Gmc. *deupaz, from PIE *d(e)u- "deep, hollow" (cf. O.C.S. duno "bottom, foundation," O.Ir. domun "world," via sense development from "bottom" to "foundation" to "earth" to "world"). Figurative sense was in O.E.; extended 16c. to color, sound. Deep pocket "wealth" is from 1951. Deep-freeze was a registered trademark (U.S. Patent Office, 1941) of a type of refrigerator; used generically for "cold storage" since 1949. To go off the deep end "lose control of oneself" is slang first recorded 1921, probably in reference to the deep end of a swimming pool, where a person on the surface can no longer touch bottom. When 3-D films seemed destined to be the next wave and the biggest thing to hit cinema since "talkies," they were known as deepies (1953). The gods have spared us.