Related Clues:

• Book jacket foldover
• Dr. Dentons feature
• Wing feature
• Do part of the chicken dance
• Tent door
• Try to stay up?
• Exercise, as wings
• Airplane wing part
• Wing movement
• Do a chicken dance move
• What bird wings do
• Part of an envelope
• Pajamas' rear opening
• Flag sound
• Opening in some pajamas, once