I. exclamation used to encourage or draw attention to the performance of an acrobatic feat. • alley-oop, straight into the lake.
II. noun (also alley-oop pass) —
[Basketball] a high pass caught by a leaping teammate who tries to dunk the ball before landing.
• she could catch alley-oops all day.
• he took an alley-oop pass from Vaughn.
– origin early 20th cent.: perhaps from French allez! ‘go on!’ + a supposedly French pronunciation of up.