A triad is a group of THREE people or things. The crossword solutions for this term include 'threesome' (9 letters), 'TRIO' (4 letters), 'TRILOGY' (7 letters), 'THREE' (5 letters), 'TRINITY' (7 letters), 'CHORD' (5 letters), 'TERN' (4 letters), and 'TRINE' (5 letters). A threesome is a group of THREE people, while a TRIO is a group of THREE musicians. A TRILOGY is a set of THREE related works, such as books or films. The word 'THREE' is simply the number THREE. The TRINITY is a Christian concept of the THREE persons of God in one being. A CHORD is a combination of THREE or more notes played together. A TERN is a type of sea bird, and a TRINE is an astrological aspect involving THREE planets.