scruple (n.) Look up scruple at Dictionary.com
1520s, from O.Fr. scrupule (14c.), from L. scrupulus "uneasiness, anxiety, pricking of conscience," lit. "small sharp stone," dim. of scrupus "sharp stone or pebble," used figuratively by Cicero for a cause of uneasiness or anxiety, probably from the notion of having a pebble in one's shoe. The verb meaning "to have or make scruples" is attested from 1620s. A more literal L. sense of "small unit of weight or measurement" is attested in English from late 14c.