KEY: Ebullition.

SYN: Boiling, effervescence, outburst, paroxysm, eruption.

ANT: Refrigeration, cooling, subsidence, composure.

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KEY: Eccentric.

SYN: Peculiar, singular, idiosyncratic, flighty, aberrant, anomalous, wayward, strange, irregular, abnormal, odd, whimsical, erratic.

ANT: Regular, ordinary, customary, normal, common, usual, unnoticeable, unremarkable.

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KEY: Echo.

SYN: Reverberation, resonance, repetition, imitation, answer.