lissome

Lissome (sometimes spelled "lissom") is a gently altered form of its synonym, "lithesome." While "lissome" tends to be the more popular choice these days, the two words have similar pasts. They both appeared in the second half of the 18th century, and they both trace back to the much older "lithe" ("supple" or "graceful"), which first appeared in English during the 14th century and comes from an Old English word meaning "gentle." "Lissome" can also be an adverb meaning "in a supple or nimble manner," but this use is rare.