What is the X in X-mas?
1520s, "to strike obliquely" (against something), alteration of slenten "slip sideways" (c.1300), perhaps via a Scandinavian source (cf. Swedish slinta "to slip," Norwegian slenta "to fall on one side"), from Proto-Germanic *slintanan. Intransitive sense of "to slope, to lie obliquely" is first recorded 1690s; transitive sense of "to give a sloping direction to" is from 1805. Related: Slanted; slanting. As an adverb from late 15c.; as an adjective from 1610s. Slant rhyme attested from 1944.
1650s, "an oblique direction or plane" (originally of landforms), from slant (v.). Meaning "a way of regarding something" is from 1905. Derogatory slang sense of "a slant-eyed Asian person" is recorded from 1943, from earlier slant-eyes (1929).
A style or register of language consisting of terms that can be substituted for standard terms of the same conceptual meaning but having stronger emotive impact than the standard terms, in order to express an attitude of self-assertion toward conventional order and moral authority and often an affinity with or membership in occupational, ethnic, or other social groups, and ranging in acceptability from sexual and scatological crudity to audacious wittiness (see Preface)
[mid-1700s+ British; origin unknown; probably related to sling, which has cognates in Norwegian that suggest the abusive nature of slang; the British dialect original term slang meant both ''a kind of projectile-hurling weapon'' and ''the language of thieves and vagabonds,'' reinforcing the connection with ''sling'']