(n): any weight unit used in pharmacy; an ounce is equal to 480 grains and a pound is equal to 12 ounces
(n): uneasiness about the fitness of an action
(n): a vague unpleasant emotion that is experienced in anticipation of some (usually ill-defined) misfortune
(n): an ethical or moral principle that inhibits action
(n): a rule or standard especially of good behavior
(v): hesitate on moral grounds
(v): interrupt temporarily an activity before continuing
(v): raise scruples
(v): worry unnecessarily or excessively
(v): have doubts about
(v): place in doubt or express doubtful speculation
Reminds me of an old joke: A guy is chatting up a girl in a bar, and after a while he invites her back to his apartment. "Oh, no," the girl says. "I have scruples". "That's okay," the guy says. "I've had my shots."
Something that is small--a small irritant that causes anxiety and restrains behavior, or a small unit of measure; original literal meaning was "a small stone"