What is the X in X-mas?
1844, "a drink of liquor," earlier "a sniff," from a Scottish and northern English survival of an obsolete verb snift meaning "to sniff, snivel" (mid-14c.), of imitative origin (cf. sniff (v.)). Meaning "large bulbous stemmed glass for drinking brandy" is from 1937. The association of "drinking liquor" with words for "inhaling, snuffling" (e.g. snort (n.), snootful) is perhaps borrowed from snuff-taking and the nasal reaction to it.
Contemptible; mean; nasty, esp in an insinuating way • Now used nearly exclusively in reference to remarks and persons who make them: A woman gets nothing but snide remarks about her driving skills
[1859+; origin unknown]