In a way that is intentional, planned, or deliberate; on purpose.
From designed (past tense of design, meaning planned intentionally) plus -ly (adverb suffix). Shows how English uses -ly to turn adjectives into adverbs modifying actions or states.
'Designedly' is more formal than 'on purpose' or 'intentionally,' and it's exactly what you'd use in a legal document where you need to prove someone acted deliberately and with forethought—it has weight.
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