faithful

• faithfull (archaic)

From Middle English feithful, equivalent to faith +‎ -ful.

• IPA^(key): /ˈfeɪθ.fəl/

• Audio (US):

  (file)

faithful (comparative more faithful, superlative most faithful)

1. Loyal; adhering firmly to person or cause.

   My dog is very faithful: he doesn't like to be petted by anybody else.

2. Having faith.
   • 2009, Paul Lakeland, Church: Living Communion, page 162:

     The application of the old discipline, say the conservatives, would probably produce a smaller but more faithful Church.

3. Reliable; worthy of trust.

   My servant is very faithful.

4. Consistent with reality.

   I would consider that a very faithful reproduction.

5. Engaging in sexual relations only with one's spouse or long-term sexual partner.

   They had been faithful to each other all of their married life.

   • 1976, The Missouri Breaks:

     She wanted to be free to explore casual affairs, but her man had to be faithful.

6. (mathematics) Injective in specific contexts, e.g. of representations in representation or functors in category theory.
7. (ring theory, of a module) Whose annihilator is zero.

• go to the wall for someone
• stand by
• true

faithful (plural faithfuls)

1. (in the plural) The practicing members of a religion or followers of a cause.

   The faithful pray five times a day.

   • 1984, 2:11:25 from the start, in Dune‎ (Science Fiction), spoken by Paul Atreides, →OCLC:

     We Fremen have a saying: God created Arrakis to train the faithful. One cannot go against the word of God.

2. Someone or something that is faithful or reliable.
   • 2009 September 30, Bruce DeMara, “Shaw's comedy gets teeth”, in Toronto Star‎:

     Earlier this year, as the recession put a damper on ticket sales, Maxwell said the easy route would have been to go for the tried-and-true old faithfuls.

• “old faithful”, in Collins English Dictionary.