upbeat
nounAn unaccented beat or beats that occur before the first beat of a measure.
nounThe upward stroke made by a conductor to indicate the beat that leads into a new measure.
adjectiveOptimistic.
adjectiveHappy; cheerful.
adjectiveHaving a
Having a
An
pleasantly (even unrealistically) optimistic
nounan unaccented beat (especially the last beat of a measure)
nouna contented state of being happy and healthy and prosperous