fidelity
The definition for fidelity is "State of being faithful." Used in a sentence: Unlike her fickle friend Benji, May Belle was known for her fidelity.
implement
The definition for implement is "To carry out or accomplish." Used in a sentence: All Randolph needed to implement his plan was a moonless night and a long rope.
ploy
The definition for ploy is "A contrived plan." Used in a sentence: Sarah thought George's ploy of borrowing her notes was a cowardly way to ask her out.
regale
The definition for regale is "To amuse." Used in a sentence: My clever brother Jeffrey regaled the dinner guests with tales of his adventures.
servile
The definition for servile is "Fearfully submissive." Used in a sentence: Felicia's servile attitude annoyed her boss, who preferred an assistant with more backbone.