dusk (n.)youdaoicibaDictYouDict
c. 1200, dosk "obscure, to become dark," perhaps from Old English dox "dark-haired, dark from the absence of light" (cognate with Swedish duska "be misty," Latin fuscus "dark," Sanskrit dhusarah "dust-colored;" also compare Old English dosan "chestnut-brown," Old High German tusin "pale yellow") with transposition of -k- and -s-, perhaps via a Northumbrian variant (compare colloquial ax for ask). But OED notes that "few of our words in -sk are of OE origin." A color word originally; the sense of "twilight" is recorded from 1620s.
gamer (n.)youdaoicibaDictYouDict
mid-15c., "an athlete" (mid-13c. as a surname, Johannes le Gamer), agent noun from game (v.). Meaning "one devoted to playing video or computer games" is attested by 1981 (by 1975 in reference to players of Dungeons & Dragons). Gamester is attested from 1580s but also sometimes meant "prostitute" (compare old slang The Game "sexual intercourse" (by 1930s), probably from the first game ever played "copulation"). From 1550s as "a gambler." Gamesman is from 1947.
Quite a few of the gamers we've encountered during our monthly strolls down "Arcade Alley" suffer the same chronic frustration: finding enough opponents to slake their thirst for endless hours of play. ["Video" magazine, May 1981]
to (prep.)youdaoicibaDictYouDict
Old English to "in the direction of, for the purpose of, furthermore," from West Germanic *to (cognates: Old Saxon and Old Frisian to, Dutch too, Old High German zuo, German zu "to"), from PIE pronominal base *do- "to, toward, upward" (cognates: Latin donec "as long as," Old Church Slavonic do "as far as, to," Greek suffix -de "to, toward," Old Irish do, Lithuanian da-), from demonstrative *de-.

Not found in Scandinavian, where the equivalent of till (prep.) is used. In Old English, the preposition (go to town) leveled with the adverb (the door slammed to) except where the adverb retained its stress (tired and hungry too); there it came to be written with -oo (see too).

The nearly universal use of to with infinitives (to sleep, to dream, etc.) arose in Middle English out of the Old English dative use of to, and it helped drive out the Old English inflectional endings (though in this use to itself is a mere sign, without meaning).

Commonly used as a prefix in Middle English (to-hear "listen to," etc.), but few of these survive (to-do, together, and time references such as today, tonight, tomorrow -- Chaucer also has to-yeere). To and fro "side to side" is attested from mid-14c. Phrase what's it to you "how does that concern you?" (1819) is a modern form of an old question:
Huæd is ðec ðæs?
[John xxi:22, in Lindisfarne Gospel, c.950]