achoo

interj. sound made when sneezing

Photic sneeze reflex is a medical condition by which people sneeze with sudden exposure to bright light, and possibly also to sneeze many times consecutively. It is also referred to as photic sneeze response, sun sneezing, photogenic sneezing, the photosternutatory reflex, or even whimsically as ACHOO syndrome with its related backronym Autosomal dominant Compelling Helio-Ophthalmic Outburst syndrome. The condition occurs in 17% to 35% of humans. The condition is passed along genetically as an autosomal dominant trait.
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v. trample, tread, step on

AHCHOO [STARNUTO]