Merriam-Webster's Collegiate® Dictionary, 11th Edition
SCRUPLE
I. noun
Etymology: Middle English scrupil, scriple, from Anglo-French scruple, from Latin scrupulus a unit of weight, diminutive of scrupus sharp stone
Date: 14th century
see: weight a minute part or quantity ; iota ,
II. noun
Etymology: Middle English scripil, scrupill, from Anglo-French scruble, from Latin scrupulus, diminutive of scrupus source of uneasiness, literally, sharp stone
Date: 15th century
an ethical consideration or principle that inhibits action, the quality or state of being scrupulous, mental reservation, see: qualm
III. intransitive verb (scrupled; scrupling)
Date: 1627
to have scruples, to show reluctance on grounds of conscience ; hesitate