•A graph in which every node has three branches, and the edges cannot be coloured in fewer than four colours without two edges of the same colour meeting at a point.
•A fluke or unrepeatable result or detection in an experiment.
Noun sense “snide remark” as back-formation from snarky (1906), from obsolete snark (“to snore, snort”, verb) (1866), from Middle English *snarken (“to snore”), from Proto-West Germanic *snarkōn, equivalent to snore + -k. Compare Low German snarken, North Frisian snarke, Swedish snarka, German schnarchen, and English snort and snore. Of Germanic origin, but ultimately onomatopoeic.