E.N.A (erect nipple alert)

The look of having your nipples stand out, "erect"

Usually someone with ENA does not have a bra on

Lucy:Janet, that girl has a major case of E.N.A (erect nipple alert)
Janet:OMG, Luc, she totally does! That ho must have forgotten her bra!
Lucy: What else do you expect from the school slut?

by Giuseppee! Or Gipsie August 17, 2009