noun / verb
scruple
SKROO-pul/ˈskruːpl/
A hesitation about whether an action is morally right.
The woman has scruples about keeping the extra banknote mistakenly given as change.

Etymology
The “small sharp stone” became an image for an uneasy conscience, probably through the idea of a pebble in one's shoe. A scruple is that inward discomfort prompting hesitation about doing wrong.
In context
he's already we know who we're you know they know who they're dealing with a complete sadist who has no scruple about lying
More examples
- He pockets the extra change without a scruple.
- My scruples prevent me from reading her private messages.
- He does not scruple to lie when money is at stake.
Forms
scruple · scruples · scrupled · scrupling
scrupulous adjective — Careful to act honestly and morally.
unscrupulous adjective — Willing to act dishonestly or immorally.
Similar words
- qualm
- Can reflect uneasiness or doubt without a specifically moral concern.
- misgiving
- Can concern practical risks rather than questions of right and wrong.
- compunction
- Often emphasizes guilt or remorse rather than hesitation before acting.