Well this could potentially be a lot of different chords really. An Am7 add 11 has A C E G and D. Here there is no E. However, if there were then really you could just call it a good old C 6/9 chord. Pro tip: many chords can be called multiple names depending on harmonic function, inversion, interpretation, etc. Forrrrr example: all sus4 chords have the same notes as a respective sus2 chord - just in different inversions. Orrrr, my good friend, did you know that all min7 chords could be Maj6 chords if used in a different context. Like Cmaj6 is C E G and A. And, what do you know, Amin7 is A C E and - you guessed it… G! So going back to the A min 7 add 11, the 11 would just be that D in the context of a min 7 add 11 chord. Or depending on your context, that D would be the 9 in a C 6/9 chord. Remember, it really is just about what you do with the chord that determines it’s identity. Even a major chord can sound sad.