"temporary marked increase in the birth rate," coined 1941 from baby (n.) + boom (n.2); derivative baby-boomer (member of the one that began in the U.S. in 1945) is recorded by 1963 (in newspaper articles when they began to approach college age); earlier it had sometimes meant "a young kangaroo."

"one who cares for the infants of those unable or unwilling to do so themselves," 1868, from baby (n.) + farmer. Related: Baby-farm.

"like a baby, extremely childish," 1753, from baby (n.) + -ish. Earlier in same sense was babish (1530s). Related: Babyishness.

mid-14c., Babilon, representing the Greek rendition of Akkadian Bab-ilani "the gate of the gods," from bab "gate" + ilani, plural of ilu "god" (compare Babel). The Old Persian form, Babiru-, shows characteristic transformation of -l- to -r- in words assimilated from Semitic.

The English word also was formerly applied by Protestants to the Church in Rome, in reference to the woman "arrayed in purple and scarlet" in Revelation xvii.5 ("And upon her forehead was a name written, Mystery, Babylon the Great, the mother of harlots and abominations of the earth").

"inhabitant of Babylonia; a Chaldean," 1560s; see Babylon + -ian. From 1630s as an adjective. Earlier in the adjectival sense was Babylonical (1530s).

also baby-sit, "watch and tend to a child while its parents are away," 1947, from baby (n.) + sit (v.); the figurative use (often contemptuous) is by 1968. Babysitting (n.) is attested from 1946.

also baby-sitter, "person who looks after a child or children while the parents are away," 1914, from baby (n.) + agent noun from sit (v.). Short form sitter is attested from 1937.

1910, name for a brand of West Indian rum produced by Compania Ron Bacardi, originally of Cuba.

1620s, "university degree of a bachelor," from Modern Latin baccalaureatus, from baccalaureus "student with the first degree," an alteration of Medieval Latin baccalarius "one who has attained the lowest degree in a university, an advanced student lecturing under his master's supervision but not yet having personal licence."

The Medieval Latin word is of uncertain origin; it likely has been altered by folk etymology or word-play, as if from bacca lauri "laurel berry" (laurels being awarded for academic success). Perhaps it is ultimately from Latin baculum "staff" (see bacillus), which the young student might carry. Or it might be a re-Latinization of bachelor in its academic sense.

In modern U.S. usage, baccalaureate usually is a shortening of baccalaureate sermon (1864), a religious farewell address to a graduating class at an American college. This is from the word's adjectival sense of "pertaining to the university degree of bachelor."

card game, 1848, from French baccara (19c.), which is of unknown origin. Baccarat is the name of a town in France that was noted for glass-making.