sedentary (adj.)

1590s, "remaining in one place," from Middle French sédentaire (16c.) and directly from Latin sedentarius "sitting, remaining in one place," from sedentem (nominative sedens), present participle of sedere "to sit; occupy an official seat, preside; sit still, remain; be fixed or settled," from PIE root *sed- (1) "to sit." Of persons, the sense "not in the habit of exercise" is recorded from 1660s.