Scruple

A weight of twenty grains; the third part of a dram.

Hence, a very small quantity; a particle.

Hesitation as to action from the difficulty of determining what is right or expedient; unwillingness, doubt, or hesitation proceeding from motives of conscience.

To be reluctant or to hesitate, as regards an action, on account of considerations of conscience or expedience.

To regard with suspicion; to hesitate at; to question.

To excite scruples in; to cause to scruple.

uneasiness about the fitness of an action (particularly for reasons of ethics, morals or propriety)