A word to express one's interest in something. Normally used by girls when subtly stalking hotties on the street; or when they're shopping and find something exceptionally cute or sexy, such as clothing.
Friend #1: "Check out that hottie across the street!"
Friend #2: "Ooer!"
Friend #1: "Look at this adorable Guess wallet I just found!"
Friend #2: "Ooer, very sexy."