commemorate
The definition for commemorate is "To mark by a ceremony." Used in a sentence: Each year, the Franklins commemorate their anniversary by visiting the site of their first date.
demeanor
The definition for demeanor is "Behavior towards others." Used in a sentence: Carlos was well liked because of his charming demeanor.
extenuating
The definition for extenuating is "Partially excusing." Used in a sentence: The extenuating circumstance of Calvin's illness caused the teacher to excuse his lateness.
gravity
The definition for gravity is "Importance, significance." Used in a sentence: Understanding the gravity of his error, Ken offered his humblest apology.
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.