Askew means crooked, and not straight as it should be. Hang askew, his hat askew, knocked askew.
The should is part of it — a thing is only askew if it was meant to be straight. It goes after the verb or the noun rather than before, so you say the picture hangs askew and not an askew picture. Note the a- prefix, as in adrift and astray.
1adverbaskewCrooked, and not straight as it should be.
“His tie was askew and his shirt was hanging out.”
askew is a position.
Proto-Germanic
*skiuhijaną — to frighten
Frankish
*skiuhan — to dread; to avoid, shun
Old French
eschuer
fro-nor
escuer
Middle English
skeuen
English
skew
English, today
askew
Built from
From a- + skew. skew The verb is derived from Middle English skeuen, skewe, skewen (“to run at an angle or obliquely; to escape”), from fro-nor escuereskieuer, eskiuer, eskiuwer, eskuer, variants of Old French eschuer, eschever, eschiver (“to escape, flee; to avoid”) (modern French esquiver (“to dodge (a blow), duck; to elude, evade; to slip away; to sidestep”)), from Frankish skiuhan (“to dread; to avoid, shun”), from Proto-Germanic skiuhijaną (“to frighten”). The English word is cognate with Catalan esquiu (“evasive, shy”), Danish skæv (“crooked, slanting; skew, wry”) (> Norwegian Bokmål skjev), Dutch scheef (“crooked, slanting”), Norwegian - skeiv (“crooked, lopsided; oblique, slanting; distorted”), stq skeeuw (“aslant, slanting; oblique; awry”), and is a a doublet of eschew. The adjective and adverb are probably derived from the verb and/or from askew, and the noun is derived from either the adjective or the verb.
Etymology from Wiktionary, CC BY-SA