sisterless,a.|ˈsɪstəlɪs| [f. sister n. + -less.] Having no sister. 1856Mrs. Craik J. Halifax ii, Brotherless, sisterless, and friendless as I was.1875W. Cory Lett. & Jrnls. (1897) 389 I'd like to end my life that way, motherless, wifeless, and sisterless.