'snub' originates from Dutch or Low German, specifically the word 'snubben' (or similar forms), where that verb meant 'to check, cut short, or rebuke'.

'snub' changed from Middle Dutch/Low German 'snubben' and entered English in the early modern period as the verb 'snub' and the noun/adjective senses developed afterward.

Initially, it meant 'to check or cut short' or a sense of 'short, turned up' (for the adjective sense); over time it evolved into the social sense of 'to rebuff or treat coldly', which is the predominant modern meaning.