"pertaining to a tailor," 1823, from Modern Latin sartorius, from Late Latin sartor "tailor," literally "patcher, mender," from Latin sart-, past participle stem of sarcire "to patch, mend." Sartorius as the name of the long leg muscle is because it is used in crossing the legs to bring them into the position needed to sit like a tailor. Related: Sartorially.