Thrice is defined as something that happened three times, or three times stronger or better.(adverb)
See thrice in Webster's New World College Dictionary
Origin: ME thries < thrie (< OE thriwa, thrice, akin to threo, three) + -(e)s, adv. gen. suffix, after ones (see once)
See thrice in American Heritage Dictionary 4
Origin: Middle English thries
Origin: , adverbial genitive of thrie
Origin: , from Old English thrīga; see trei- in Indo-European roots.
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