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n. Music An unaccented beat or beats that occur before the first beat of a measure. Also called anacrusis, pickup.

n. Music The upward stroke made by a conductor to indicate the beat that leads into a new measure.

adj. Informal Optimistic: an upbeat business forecast.

adj. Informal Happy; cheerful.

adj. Having a fast pace, tempo, or beat.

adj. Having a positive, lively, or perky tone, attitude, etc.

n. An unaccented beat at the start of a musical phrase.

adj. pleasantly (even unrealistically) optimistic

n. an unaccented beat (especially the last beat of a measure)

n. a contented state of being happy and healthy and prosperous

"Then again, what you refer to as "upbeat" we might describe as "frenzied.""

optimistic   

downbeat   

beat    rhythm    musical rhythm   

optimistic    chatty    light-hearted    easygoing    bouncy    jokey    carefree    catchy    pessimistic    companionable