Meanings (ES + gloss)
ídem
That which was stated before, the aforesaid, the above, the same, likewise.
[...] they entered a dismal-looking parlour, whose brick-red walls and ditto curtains were scantily lighted by a single lamp, though it was of the last new patent—[…]
[…]a spacious table in the centre, and a variety of smaller dittos in the corners:[…]
signo de ídem
The ditto mark, 〃; a symbol, represented by two apostrophes, inverted commas, or quotation marks (" "), indicating that the item preceding is to be repeated.