"decimal part of a logarithm," 1865, from Latin mantisa "a worthless addition, makeweight," perhaps a Gaulish word introduced into Latin via Etruscan (compare Old Irish meit, Welsh maint "size"). So called as being "additional" to the characteristic or integral part. The Latin word was used in 17c. English in the sense of "an addition of small importance to a literary work, etc."
1975, transitive, "start up (a computer) by causing an operating system to load in the memory," from bootstrap (v.), a 1958 derived verb from bootstrap (n.) in the sense of "fixed sequence of instructions to load the operating system of a computer" (1953).
This is from the notion of the first-loaded program pulling itself (and the rest) up by the bootstrap. The intransitive use, of a computer operating system, is from 1983. Related: Booted; booting.
former transliteration of the name of the Chinese capital city, now (in the pinyin system) called Beijing. In the Wade-Giles system it was Peiping; the form Peking pre-dates Wade-Giles and was formed by the old British-run, Hong Kong-based Chinese postal system. Peking duck, "large domestic duck of white plumage and orange beak and legs," is attested from 1880.