I learned that any simultaneous sounding of three or more notes is a chord--that is a chord doesn't have to be consonant--it can be dissonant like a suspended one. Technically (ie nitpickingly) two notes sounded simultaneously do not constitute a chord; but an interval. However fingerstyle guitar often depends upon unplucked strings sounding and the letters on top of the tab, lyrics, or whatever take that into account. So even if you play C and G, your music might say it is a "C" chord and you finger the "E", so it rings instead of the open "D" ringing. I have done some experimenting that way. If a chord is fingered but one note is left out of the plucking, it sounds very different from when the left out string is muted or when it is not fingered.

Murray