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.
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.
fragile
The definition for fragile is "Delicate." Used in a sentence: Jade placed the fragile vase out of reach of her rambunctious boys.
grandiose
The definition for grandiose is "With an affectation of grandeur." Used in a sentence: The sweeping, grandiose staircase looked preposterous in the modest entry hall.
prudent
The definition for prudent is "Marked by wisdom, shrewd." Used in a sentence: Manny was happy she followed Greg's prudent advice to study, as the test was difficult.