Petty thing to pick (3)
I believe the answer is:
nit
(Other definitions for nit that I've seen before include "Young louse" , "Cause of much head-scratching" , "Muggins" , "Hair louse" , "Louse-egg" .)
I believe the answer is:
nit
(Other definitions for nit that I've seen before include "Young louse" , "Cause of much head-scratching" , "Muggins" , "Hair louse" , "Louse-egg" .)