An "aberration" is something that occurs outside the normal range. You might say, "Since he normally hit home runs, Dan's strikeout was an aberration." "Deviation" has a similar meaning of something that happens outside of the normal course of events. "Fleeting" is an adjective meaning happening for a short brief time, and as such cannot be synonymous. "Freezing" is an adjective used to describe a temperature below zero degrees celsius or the feeling of being very cold. An "imitation" is a copy.

"Nuance" is a noun which means fine shade of meaning. Your acting teacher might tell you to pay attention to the nuances of an actor's performance. This means that you are paying attention to the subtle differences in vocal tone, emotion or facial expressions that the actor uses to enhance understanding of his performance. "Subtlety" is a noun which means being delicate or precise. This is a similar meaning to "nuance."

"Differentiate" is a verb meaning to recognize differences between things. You may use your skills of differentiation to determine the fine nuances in the actor's performance, but it is the act of making the determination, not the fine shades of meaning themselves.

"Enhance" is a verb which means to make better.

"Ensconce" is a verb which means to settle in a secret place.

"Obfuscate" is a verb which means to make unclear; to confuse or bewilder.

An "enigma" is a noun meaning mystery or puzzle. "Puzzle" is also a noun, while "mysterious" is an adjective meaning difficult to understand. "Puzzle" is a better choice than "mysterious" because "puzzle" and "enigma" are both nouns.

"Noxious" is an adjective meaning poisonous; harmful.

"Disoriented" is also an adjective. It means not oriented; confused. You might become disoriented in the forest and walk in the opposite direction of your campsite.

"Reliable" is an adjective meaning trustworthy.

"Laud" means to praise highly.

"Propound" means to put forward or offer for consideration.

"Chortle" means to chuckle gleefully, so "laugh" is the correct answer because it is the closest synonym amongst the given answer choices.

"Denote" means to be a sign of, or to indicate.

"Cajole" means to persuade using coaxing and flattery.

"Accentuate" means to highlight or emphasize. "Undermine" means to weaken. "Confront" means to come face-to-face with, or to challenge. "Amass" means to accumulate or gather. "Frustrate" to foil or block a plan or some action.

"Ostracize" means exclude or banish someone from something, so "exclude" is the correct answer. Considering the other answer choices, "include" cannot be the correct answer becuase "include" means accept or welcome into a group, making it an antonym of "ostracize" and "exclude." "Birdlike" means avian, "burn" means set on fire or injure with fire, and "craft," when used as a verb, means make or construct.