An augmented triad is a chord, made up of two major thirds (an augmented fifth). The term augmented triad arises from an augmented triad being considered a major chord whose top note (fifth) is raised. When using popular-music symbols, it is indicated by the symbol “+” or “aug”. For example, the augmented triad built on C, written as C+, has pitches C–E–G♯:

Source: Augmented triad – Wikipedia