"Efficient" means effective without being wasteful, so "effective" is the closest synonym.

Something that is "intricate" is complex and complicated. For clarification, an "outlier" is something or somebody that is outside of the norm; "serendipitous" means owed to good fortune.

"Contentious" means causing disagreement, debatable or controversial. For clarification, "apathetic" means not caring or unemotional; "kinetic" is an adjective that means relating to movement, "laden" means burdened, and "umbrage" is a feeling or resentment or offense.

Akin means similar or comparable. For clarification, unique means distinct and original; vie means to compete or struggle.

Something that is "outlandish" is bizarre and eccentric, so "bizarre," an adjective that means strange, is the correct answer. For clarification, "exquisite" means very beautiful, "comely" means attractive, "inspiring" means _encouraging_or motivating, and "famous" means well-known or prominent.

"Doting" means indulgent, affectionate or loving.

"Content" means happy or satisfied.

"Envious" means having envy, or desiring a trait possessed by someone else.

"Adorable" means sweet and cute or lovable.

"Hateful" means nasty, cruel or despicable.

"Obedient" and "compliant" both describe a willingness to follow rules. "Gullible" and "skeptical" are antonyms, and "creative" means imaginative. "Woebegone" means sorrowful.

"Praiseworthy" and "commendable" are synonyms. "Vile" means foul or disgusting. "Immense" means huge or massive. "Supreme" means of the highest rank and is not quite a synonym for "praiseworthy," although something "supreme" may also be deserving of praise. "Trustworthy" means able to be trusted.

"Keen" means either eager or sharp-witted. So, "sharp-witted" is the correct answer. For clarification, "banished" means sent away, and is an antonym of "welcomed," which means amiably received. "Ill-tempered" means crabby or cranky, and "jocular" means jovial, playful, or funny.

Someone who is "altruistic" is very charitable and inclined towards generosity. For clarification, "mousy" means dull or timid; "tenuous" means uncertain; "haughty" means arrogant; "decadent" means corrupt and luxurious.