Here is a word that I haven’t heard used often, but I could guess the meaning by the context in which it was used in “The Missing Three-Quarter” in The Greatest Adventures of Sherlock Holmes. But I am glad I looked it up so I could know exactly what it meant.

Compunction – a feeling of guilt or moral scruple that prevents or follows the doing of something bad

Usage: “I thank heaven that my compunction at leaving poor Staunton all alone in this plight caused me to turn my carriage back and so to make your acquaintance.”