1 Retrieved October 19 2015 from http://www.acronymfinder.com/Radiology-Information-System%2fPicture-Archiving-and-Communication-System-(RIS%2fPACS).html. 2  APA style: RIS/PACS. (n.d.) Acronym Finder. ( 3 2015).
In music, a diminished triad ( Play ), also known as the minor flatted fifth (mâ­5), is a triad consisting of three minor thirds above the root â if built on C, a diminished triad would have a C, an Eâ­ and a Gâ­.
Webster Dictionary(0.00 / 0 votes)Rate this definition: 1  Triad(noun) a union of three; three objects treated as one; a ternary; a trinity; as, a triad of deities. 2  Triad(noun) a chord of three notes. 3  Triad(noun) the common chord, consisting of a tone with its third and fifth, with or without the octave.