also mockup, "model, simulation" 1919, perhaps World War I, from the verbal phrase mock up "make an experimental model" (1911), from mock (v.) + up (adv.).

1670s, of clothing, "adapted for being pinned up," from the verbal phrase (attested from mid-15c. in the sense "affix in a prominent place"), from pin (v.) + up (adv.). From 1940, in reference to pictures of "winsome young ladies in daring undress" ("Life," May 6, 1940) such as soldiers pinned up on their dugout walls, etc. The thing itself is older than the name. The noun in this sense is recorded from 1943.

"state of confusion," 1841, from the colloquial verbal phrase mix up "to confuse, entangle mentally" (1806), from mix (v.) + up (adv.). Of fighters, to mix it up "exchange blows" is by 1898.

"a working to overtake a leading rival," by 1971, probably a figurative use from U.S. football in reference to being behind in the score. From verbal phrase catch up, which was used from early 14c. in sense "raise aloft," c. 1400 as "to take up suddenly," and by 1846 in sense "get to the same point, overtake;" see catch (v.) + up (adv.).

also chinup, type of exercise, 1940, from chin (v.) + up (adv.). Earlier it was called chinning the bar and under names such as this is described by 1883.