faith·ful 
/ˈfeɪθfəl/ adjective
/ˈfeɪθfəl/ adjective [more faithful; most faithful] 1 : having or showing true and constant support or loyalty
▪ a faithful friend/companion ▪ faithful friendship ▪ the team's faithful fans ▪ a faithful dog — often + to ▪ Despite his problems, his friends have remained faithful to him. ▪ She has always remained faithful to the values she learned as a child. 2 : deserving trust : keeping your promises or doing what you are supposed to do
▪ a faithful worker/servant ▪ She has provided the company with many years of faithful service. — often + to ▪ He began to keep a journal and was faithful to it for years. [=he continued to write in his journal for many years] ▪ He was not faithful to his word. [=he did not do what he said he would] 3 : not having sex with someone who is not your wife, husband, girlfriend, or boyfriend
▪ a faithful husband/wife ▪ He insists that he has always been faithful to his wife. 4 : exact and accurate
▪ The movie was a faithful adaptation of the book. ▪ a faithful copy — often + to ▪ The movie is faithful to the book. [=the story told in the movie closely matches the story told in the book]
▪ a faithful friend/companion ▪ faithful friendship ▪ the team's faithful fans ▪ a faithful dog — often + to ▪ Despite his problems, his friends have remained faithful to him. ▪ She has always remained faithful to the values she learned as a child.
▪ a faithful worker/servant ▪ She has provided the company with many years of faithful service. — often + to ▪ He began to keep a journal and was faithful to it for years. [=he continued to write in his journal for many years] ▪ He was not faithful to his word. [=he did not do what he said he would]
▪ a faithful husband/wife ▪ He insists that he has always been faithful to his wife.
▪ The movie was a faithful adaptation of the book. ▪ a faithful copy — often + to ▪ The movie is faithful to the book. [=the story told in the movie closely matches the story told in the book]
the faithful 1 : the people who believe or participate in a religion
▪ The faithful gather here each year to celebrate together. 2 : the people who are loyal members or supporters of a group or organization
▪ The faithful come out and cheer for the team every year. ▪ The convention was packed with the Republican/Democratic faithful.
▪ The faithful gather here each year to celebrate together.
▪ The faithful come out and cheer for the team every year. ▪ The convention was packed with the Republican/Democratic faithful.
— faith·ful·ly /ˈfeɪθfəli/ adverb
▪ My friends have supported me faithfully. ▪ He faithfully submitted all the proper forms. ▪ The model faithfully [=accurately] reproduces the original building.
/ˈfeɪθfəli/ adverb ▪ My friends have supported me faithfully. ▪ He faithfully submitted all the proper forms. ▪ The model faithfully [=accurately] reproduces the original building.
— faith·ful·ness noun [noncount]
