"commence."
Countdown and commencement are synonyms for starting. They begin with the letter c.
The word is center.
sorry but there are no synonyms starting with A.
Cheerful and contented are synonyms for happy.
Cymbals go boom.
Palace and prison are synonyms for home. They begin with P.
zap - kill
ample
remix
conception
go on www.synonym.com 4 synonyms & antonyms
Synonyms for "commencing" are "starting" or "beginning".