The name Lettice is a girl's name of English origin. Lettice and is often added to lists like British Girl Names and discussed in our forums with posts like "The Makeover Baby Name Game".
From the experts:
Lettice is still occasionally heard in upper-class British families, but we fear it would cause too much salad-green teasing to be considered in the U.S. Calling your little Lettice Lettie could help make the name more user-friendly, or go all the way to the original Letitia.