windshield-wipering
n.— «They run across the top, they go deep, they shake their head. They do what I call “windshield-wipering,” when they stick their bill out and shake it back and fourth.» —“Stuart fishermen catch 620-pound swordfish off Jupiter Inlet” by Gabriel Margasak in Stuart TCPalm.com (Florida) Aug. 23, 2005. (source: Double-Tongued Dictionary)