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.