petty (adj.)

late 14c., "small, little; minor, trifling, insignificant," from Old French petit "small, little, young, few in numbers" (11c.), which is probably from the stem of Late Latin pitinnus "small," a word of uncertain origin; it corresponds to no known Latin form and perhaps is from a Celtic root pett- "part, piece, bit" also found in Italian pezza, English piece.

Attested as a surname from 1086. Replaced by petty in most usages, except in established forms such as petit bourgeois "conventional middle-class" (1832; used in English by Charlotte Brontë earlier than by Marx or Engels); petit mal ("mild form of epilepsy," 1842, literally "little evil"); petit-maître ("a fop, a dandy," 1711, literally "little master"); and petit four "small, fancy dessert cake" (1884), which in French means "little oven," from Old French four "oven," from Latin furnus. In Middle English a petiteskole (mid-15c.) was a school for young children.

"domesticated or tamed animal kept as a favorite," 1530s, originally in Scottish and northern England dialect (and exclusively so until mid-18c.), a word of unknown origin. Sense of "indulged or favorite child" (c. 1500) is recorded slightly earlier than that of "animal kept as a favorite" (1530s), but the latter may be the primary meaning. Probably associated with or influenced by petty.

Know nature's children all divide her care;

The fur that warms a monarch warm'd a bear.

While man exclaims, 'See all things for my use!'

'See man for mine!' replies a pamper'd goose:

[Alexander Pope, "Essay on Man"]

It is an amiable part of human nature, that we should love our animals; it is even better to love them to the point of folly, than not to love them at all. [Stevie Smith, "Cats in Colour," 1959]

In early use typically a lamb brought up by hand (compare cade); but the earliest surviving reference lists "Parroquets, monkeys, peacocks, swans, &c., &c." As a term of endearment by 1849. Teacher's pet as a derogatory term for a teacher's favorite pupil is attested by 1854, American English. Pet-shop "shop selling animals to be kept as pets" is from 1928.