guitar chord
E♭dim
Two minor thirds stacked. The fifth is diminished, so it cannot be dropped without losing the chord.
Written the other way round it is D♯dim — the same twelve keys on a piano, a different piece of notation.
Every fingering that fits a hand
xx1242
hard
x6787x
hard
xxdbab
hard
bcdbxx
moderate · barre
What is true of it
E♭dim is E♭, G♭ and B♭♭ — 1, b3 and b5 counted from E♭.
B♭♭ is a double flat, and it has to be: every letter from E♭ upwards is used once, so the b5 cannot be written any other way.
The easiest of the 4 fingerings below is xx1242: 4 fingers, held at the 1st fret.
None of them uses an open string, so this chord moves up the neck unchanged — the same shape 1 fret higher is the chord a semitone above.
1 of the 4 need a barre.
2 strings stay silent.
Where its notes are on the neck
The brass dots are E♭, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
E♭dim/G♭
2012xx
E♭dim/B♭♭
x04242
An inversion is the same chord with a different note lowest. The name changes to a slash name because the bass is what a listener hears as the foundation.