Английский Этимологический словарь - pit (1)

- "hole," O.E. pytt "water hole, pit," from W.Gmc. *puttjaz, early borrowing from L. puteus "well, pit, shaft." The verb meaning "set against, oppose," is first recorded 1760, from the pits (1568) where cock fights and dog fights were held (cf. Pit-bull terrier first recorded 1945). This is also the notion behind the meaning "the part of a theater on the floor of the house" (1649). Pit of the stomach is from the slight depression there between the ribs. Pitfall is mid-14c., originally an animal trap; extended sense of "any hidden danger" is early 15c. Pits "the worst," first attested 1953, U.S. slang, said to be a shortened form of armpits.