lockout (n.)

c. 1300, "to fasten with a lock, shut or confine with a lock." The sense is narrowed from that of Old English lucan "to lock, to close" (class II strong verb; past tense leac, past participle locen), from the same verbal root that yielded lock (n.1). The form is from the noun (perhaps reinforced by Old Norse loka); the old original strong verb survived as dialectal louk, and the strong past participle locken lingered a while, as in Middle English loken love "hidden love, clandestine love" (early 14c.).

The Old English verb is cognate with Old Frisian luka "to close," Old Saxon lukan, Old High German luhhan, Old Norse luka, Gothic galukan. Meaning "to fasten parts together" is from late 14c., originally of armor; of persons, "to embrace closely," from mid-14c. Related: Locked; locking. Locked "securely established" is from early 15c. To lock (someone) in "shut in a place" is from c. 1400. Slang lock horns "fight" is from 1839.

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.