noun

• (pharmacy) A weight of ¹⁄₂₈₈ of a pound, that is, twenty grains or one third of a dram, about 1.3 grams (symbol: ℈).
  "The Oyle ſerueth in many operations, and ſpecially in all colde diſeaſes, if they be inwardly, give thereof euerye morning one ſcruple to drinke, and if they be outward annoynt."
• (obsolete, by extension) A very small quantity; a particle.
  "Why euery thing adheres togither, that no dramme of a ſcruple, no ſcruple of a ſcruple, no obſtacle, no incredulous or unſafe circumſtance: What can be ſaide? Nothing that can be, can come betweene me, and the full proſpect of my hopes."
• (obsolete) A doubt or uncertainty concerning a matter of fact; intellectual perplexity.
  "There aroſe a Scruple, nay, it amount to a Queſtion, whether to attempt an Eſcape from my Patron, one that ſo dearly Loved me, ſo fairly bought me, were juſtifiable before God and Men?"

verb

• (intransitive) To hesitate or be reluctant to act due to considerations of conscience or expedience.
  "They wouldn't scruple to cheat us if given the opportunity."
• (intransitive) To excite scruples in; to cause to scruple.
  "It is granted indeed before that time, the Supream power was in Him [Charles I of England], and we were all his Subjects: and then perhaps ſome might Scruple to cut his throat, for there were lawes then in force against Regicides, but now ſince his Reſignation, (for ſo in our Tenents we hold this Act to be,) there is no ſcruple to be made, thoſe lawes against King-killers are ſuſpended, and he is now become as Samſon was without his ſtrength, […]"
• (transitive) To regard with suspicion; to question.
  "As for the writings of Heathen authors, unleſſe they were plaine invectives againſt Chriſtianity, as thoſe of Porphyrius and Proclus, they met with no interdict that can be cited, till about the year 400, in a Carthaginian Councel, wherein Biſhops themſelves were forbid to read the Books of Gentiles, but Hereſies they might read: while others long before them on the contrary ſcrupl'd more the Books of Hereticks, then of Gentiles."
• (intransitive, obsolete) To question the truth of (a fact, etc.); to doubt; to hesitate to believe, to question.
  "I do not scruple to admit that all the Earth seeth but only half of the Moon."