lobtail

lobtail [lob-teyl] Word Origin verb (used without object)

1. (of a whale) to slap the flukes against the surface of the water.

Origin of lobtail 1865–70 (as gerund); apparently lob1 in sense “to move heavily” + tail1 Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019