D defs.my
Entry 2 senses Webster, 1913

Looker

/lo͝ok'-ẽr/ · Look·er · IPA /ˈlʊk.ɚ/
01 n. One who looks.
  1. 1.
    One who looks.
  2. 2.
    A person who is physically very attractive, especially a beautiful woman.
    “Did not this fatal war affront thy coast, Yet sattest thou an idle looker-on ?” Fairfax.
Phrases & compounds
Looker-on — a spectator; an onlooker; one that looks on, but has no agency or part in an affair.