To separate things that have been joined together in a chain or sequence; to undo concatenation.
From de- + concatenate (join in a chain), from Latin concatenare (con- together + catenare from catena, chain). This is primarily a computer science term.
In programming, strings (text) are concatenated all the time to combine words, so deconcatenating splits them back apart—it's like undoing a linguistic chain link.
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