An archaic or poetic spelling of 'accomplished,' meaning skilled, refined, or having completed something successfully.
From accomplish (Old French accomplir, from Latin ad- + complere 'to fill up') plus -t as an older spelling variant. This represents an earlier stage of English orthography.
This obsolete spelling shows how fluid English was before dictionaries standardized spelling in the 1700s—the same word could be written multiple ways, and both were 'correct' because standardization hadn't happened yet.
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