An unruly lock or section of hair that sticks straight out from the skull or lies at an angle at odds with the rest of an individual's hair, like a whorl or vortex.
seta
noun
A bristle or hair
The stalk of a moss sporangium, or occasionally in a liverwort.
How often have the words cowlick and seta occurred in a corpus of books? (source: Google Ngram Viewer )