also markup, "amount added by a retailer to cover overhead and provide profit," 1899, from the verbal phrase in this sense (by 1870); see mark (v.) + up (adv.).

"advance toward maturity," 1530s, from grow (v.) + up (adv.). As a command to be sensible, from 1951.

c. 1300, "suspend (something) so that it is supported only from above;" see hang (v.) + up (adv.); telephone sense by 1911. The noun hang-up "psychological fixation" is first attested 1959, from notion of being suspended in one place.

"action of signing up; number who have signed up," 1940, from the verbal phrase meaning "to enroll, enlist," which is attested by 1903; see sign (v.) + up (adv.).

also coverup, "means or act of concealing" some event or activity, 1922, from the verbal phrase (1872), from cover (v.) + up (adv.).

from 1906 as a type of baseball hit; from pop (v.) + up (adv.). As an adjective from 1934 (of a children's book, later toasters, etc.).

"interior regions," 1680s, from up- + country (n.). As an adjective from 1810; as an adverb from 1864.

1882, from the verbal phrase; see write (v.) + up (adv.).

"a joining together or coupling," 1945, from the verbal phrase; see link (v.) + up (adv.).

1830 as the name of a children's game (OED describes it as "all-fours" when played for seven "chalks"); with capital initials, as the proprietary name of a brand of carbonated drink, it is attested from 1928.