I am writing a short story, and one of the main characters leans in for a kiss from a girl he fancies. She gives a quick, derisive laugh before slapping him. Not even a full laugh, just a short puff of air from the nose. I have asked around, and looked online, but I can’t find what this laugh is called. Is there a name for it?
Snort?
Second vote for snort.
Thanks for your help!
I had thought of ‘snort’, too. Although, I thought a snort was more of a breathing in, with a loud sound. I was thinking of a breathing out, with a quieter sound.
Hmph!
Hmph! She scoffed as she raised her hand…?
I hear in my head …
[Mrs. Krabappel]
Hah!
[/Mrs. Krabappel]
That’s a snort of derision. Or so I am told.
I’ve always called it a “Grace Adler.” 
Snicker might be another alternative.
Maybe sniffle, but that’s more associated with a runny nose. ‘A barely audible snort’ would get the point across.
I know that sound and I don’t think there’ll be any word for it. The sound (a pissed-off one?) reminds me of the quick (pissed-off) sound of the tip of the tongue against the roof of the mouth (breathed out, quickly).
bemused laugh?
You don’t really need a special name for it. I just read Black Chalk last week and he used this:
burst, puff, heave, buffet, gust, discharge, flare, surge, salvo, spurt, rupture, spate
There are a number of people here who know IPA. Can this sound be represented with it?
Assuming you don’t mean India Pale Ale, the OP said it was a nose sound, so no.
In the olden days, I think that would have been called a huff (“She huffed”). Huff has another meaning as well now, which might cause a disconnect in younger readers.
I don’t think so. It’s a voiceless nasal aspiration starting with a salpingopharyngeal stop.
I vote for scoff.
I’ve always thought of that as a chuckle. I’m not sure that fits your scenario though.
To scoff isn’t to laugh. It’s to express derision with words.