Nit – definition of nit by The Free Dictionary

NIT abbr. National Invitational Tournament nit 1 (nĭt) n. The egg of certain parasitic insects, especially a head louse. [Middle English, from Old English hnitu.] nit′ty adj. nit 2 (nĭt) n. A unit of luminance equal to one candela per square meter, measured perpendicular to the rays of the source. [From Latin nitor, brightness, from nitēre, to …

: https://www.thefreedictionary.com/nit