demeanor
The definition for demeanor is "Behavior towards others." Used in a sentence: Carlos was well liked because of his charming demeanor.
dubious
The definition for dubious is "Questionable." Used in a sentence: Karl found Kevin's claim that he was sick dubious, as he had just seen him playing football.
fickle
The definition for fickle is "Lacking constancy, changeable." Used in a sentence: The fickle Senji had a new best friend every month.
frugal
The definition for frugal is "Thrifty, cheap." Used in a sentence: The frugal shopper only bought items that were on sale.
perception
The definition for perception is "Capacity for seeing or understanding." Used in a sentence: His incredible perception made him the best detective on the force.