piano chord
D♯add9
D♯1F𝄪3A♯5E♯9
A major triad with a ninth added and no seventh — which is what tells it apart from a ninth chord.
Written the other way round it is E♭add9 — the same twelve keys on a piano, a different piece of notation.
What is true of it
D♯add9 is D♯, F𝄪, A♯ and E♯ — 1, 3, 5 and 9 counted from D♯.
F𝄪 is a double sharp, and it has to be: every letter from D♯ upwards is used once, so the 3 cannot be written any other way.
On an instrument that cannot reach all 4, the 5 goes first, in that order.