A — 1: φίλος
(Strong's #5384 — Adjective — philos — fee'-los )

primarily an adjective, denoting "loved, dear, or friendly," became used as a noun, (a) masculine, Matthew 11:19; fourteen times in Luke (once feminine, Luke 15:9 ); six in John; three in Acts; two in James, James 2:23 , "the friend of God;" James 4:4 , "a friend of the world;" 3—John 1:14 (twice); (b) feminine, Luke 15:9 , "her friends."

A — 2: ἑταῖρος
(Strong's #2083 — Noun Masculine — hetairos — het-ah'ee-ros )

"a comrade, companion, partner," is used as a term of kindly address in Matthew 20:13; 22:12; 26:50 . This, as expressing comradeship, is to be distinguished from No. 1, which is a term of endearment. Some mss. have the word in Matthew 11:16; the best have heterois, others, AV and RV, "fellows." See FELLOW.

Mark 3:21Mark 5:19
B — 1: πείθω
(Strong's #3982 — Verb — peitho — pi'-tho )

"to persuade, influence," is rendered "having made ... their friend" in Acts 12:20 , of the folks of Tyre and Sidon in winning the good will of Blastus, Herod's chamberlain, possibly with bribes. See ASSURE , B, No. 3.