snirt
To give a suppressed laugh or sharp intake of breath.
"He grins, and snirts, and thraws ye ken —
Where it comes from
Origin uncertain. Either from Middle English snurten (“to sneer; snort, snore”), a variation of snorten (“to snort”); or from Middle English *snyrten, an alteration of fnyrten, fnerten, from Old English fnǣrettan. Compare also Norwegian snurt (“vexed, peevish”), Middle English snirt (“stern, gloomy”).
Adapted from the Wiktionary entry snirt (CC BY-SA 4.0).