un·faith·ful 
/ˌʌnˈfeɪθfəl/ adjective
/ˌʌnˈfeɪθfəl/ adjective 1 : having a sexual relationship with someone who is not your wife, husband, or partner
▪ an unfaithful husband — often + to ▪ She has been unfaithful to him over the years. [=she has had sex with other people] 2 : not accurate
▪ an unfaithful translation — often + to ▪ The movie was unfaithful to the book. [=the movie did not tell the story the way it was written in the book]
▪ an unfaithful husband — often + to ▪ She has been unfaithful to him over the years. [=she has had sex with other people]
▪ an unfaithful translation — often + to ▪ The movie was unfaithful to the book. [=the movie did not tell the story the way it was written in the book]
— un·faith·ful·ness noun [noncount]
