This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
譂 combines 言 (speech) with 單, which likely contributes the sound. The exact historical development is uncertain.
With 言 (speech) on the left and 單 on the right, 譂 might suggest a kind of speech, but its meaning is unclear. Think of it as a mysterious word.
For セン, imagine a cent (coin) being talked about: cent -> セン, and the speech radical 言 hints at the discussion.