I. |häbə(n)|näb interjection
Etymology: probably alteration of earlier hob or nob, alteration of hab or nab — more at habnab
archaic — used as an informal toast in convivial drinking
II. adverb (or adjective)
also hob a nob “
archaic : in a close and friendly relationship : in a warmly companionable relationship
III.
or hob-a-nob “
archaic
variant of hobnob I