出典:Wiktionary
Attested 1956, I. BELKNAP Human Problems of State Mental Hospitals x. 177[1] In cartoon Out Our Way by J. R. Williams, there is a character by that name. Earlier examples from newspapers of the 1930s and 1940s.[2]
Presumably related to earlier worryguts.
From worry + "wart" apparently chosen for alliteration.
worrywart (複数形 worrywarts)