noun, na-adjective, noun which may take the genitive case particle 'no'
person who sweats easily; profuse sweater
Describes a person who tends to sweat a lot. Can be used as a noun or adjectivally (汗っかきな人, 汗っかきの体質).
私は汗っかきなので、夏はいつもハンカチを持ち歩いている。
I sweat easily, so I always carry a handkerchief in summer.
彼は汗っかきで、少し動いただけでもすぐに汗をかく。
He's a profuse sweater; even a little movement makes him sweat right away.
汗かき is a more general term for someone who sweats or a sweaty person, while 汗っかき emphasizes the tendency to sweat easily, often with a colloquial nuance.
Derived from 汗 (あせ, sweat) + かき (from 掻く, to scratch/sweat) with a geminate っ for emphasis, forming a colloquial noun meaning 'one who sweats easily'.