checkout n.

late 15c., in chess, "to attack the king; to put (the opponent's king) in check;" earlier (late 14c.) in a figurative sense, "to stop, arrest; block, barricade;" from check (n.1) or Old French eschequier, from the noun in French. A player in chess limits his opponent's ability to move when he places his opponent's king in check.

The other senses seem all to have developed from the chess sense, or from the noun: "To arrest, stop," then "to hold in restraint" (1620s); "to hold up or control" (an assertion, a person, etc.) by comparison with some authority or record (1690s); of baggage, etc., "to hand over in return for a check that serves as a means of identifying" (1846); "to note with a mark as having been examined, etc., mark off from a list" (1928).

Hence, to check off (1839); to check up (1883); to check in or out (in a hotel, of a library book, etc., 1909). To check out (something) "to look at, investigate" is from 1959. Related: Checked; checking.

expressing motion or direction from within or from a central point, also removal from proper place or position, Old English ut "out, without, outside," from Proto-Germanic *ūt- (Old Norse, Old Frisian, Old Saxon, Gothic ut, Middle Dutch uut, Dutch uit, Old High German uz, German aus), from PIE root *uidh- "up, out, up away, on high" (source also of Sanskrit ut "up, out," uttarah "higher, upper, later, northern;" Avestan uz- "up, out," Old Irish ud- "out," Latin usque "all the way to, continuously, without interruption," Greek hysteros "the latter," Russian vy- "out").

Sense of "to a full end, completely, to a conclusion or finish" is from c. 1300. Meaning "so as to be no longer burning or alight; into darkness" is from c. 1400. Of position or situation, "beyond the bounds of, not within," early 15c. Meaning "into public notice" is from 1540s; that of "away from one's place of residence," c. 1600. The political sense of "not in office, removed or ejected from a position" is from c. 1600. Meaning "come into sight, become visible" (of stars, etc.) is by 1610s. In radio communication, a word indicating that the speaker has finished speaking, by 1950.

As a preposition, "out of; from, away from; outside of, beyond; except; without, lacking;" mid-13c., from the adverb.

Meaning "from harmonious relations, into quarreling" (as in to fall out) is from 1520s. Meaning "from one's normal state of mind" (as in put out) is from 1580s; out to lunch "insane" is student slang from 1955. Adjectival phrase out-of-the-way "remote, secluded" is attested from late 15c. Out-of-towner "one not from a certain place" is from 1911. Out of this world "excellent" is from 1938; out of sight "excellent, superior" is from 1891. To (verb) it out "bring to a finish" is from 1580s. Expression from here on out "henceforward" is by 1942. Out upon, expressing abhorrence or reproach, is from early 15c.