A Scruple

1. (obsolete) A weight of 1⁄288 of a pound, that is, twenty grains or one third of a dram, in England about 1.3 grams (symbol: ℈).

Synonym: s.ap. (abbreviation)

2. (obsolete, by extension) A very small quantity; a particle.

Synonyms: modicum

3. (obsolete) A doubt or uncertainty concerning a matter of fact; intellectual perplexity.
4. Hesitation to act from the difficulty of determining what is right or expedient; doubt, hesitation or unwillingness due to motives of conscience.
5. A Hebrew unit of time equal to 1⁄1080 hour.