elusive
The definition for elusive is "Hard to grasp." Used in a sentence: The words to the song are elusive, as the singer tends to mumble.
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.
flaw
The definition for flaw is "An imperfection." Used in a sentence: The otherwise perfect diamond had a tiny flaw that reduced its value.
fragile
The definition for fragile is "Delicate." Used in a sentence: Jade placed the fragile vase out of reach of her rambunctious boys.
surplus
The definition for surplus is "Excess." Used in a sentence: Trevor decided to freeze the surplus chili for next week's tailgate party.