any seaweed of the genus Ulva, having large leaflike blades.
Origin of sea lettuce
First recorded in 1660–70
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for sea lettuce
Historical Examples of sea lettuce
There is sea-lettuce in the water, so there must be enough air.
Ulva, or sea-lettuce, is to be found in abundance in all our small bays and inlets at low tide.
any of various green seaweeds of the genus Ulva, which have edible wavy translucent fronds
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012