demeanor
The definition for demeanor is "Behavior towards others." Used in a sentence: Carlos was well liked because of his charming demeanor.
elate
The definition for elate is "To fill with joy." Used in a sentence: It elated Margaret to be awarded first place in the science fair.
fickle
The definition for fickle is "Lacking constancy, changeable." Used in a sentence: The fickle Senji had a new best friend every month.
heinous
The definition for heinous is "Shockingly evil." Used in a sentence: Eduardo's heinous betrayal of Lydia shocked even Latasha, who knew his evil ways.
polarize
The definition for polarize is "To break up into opposing groups." Used in a sentence: Thelma tended to polarize discussions rather than to encourage compromise.