Extended Strong's Greek Lexicon (Abbott-Smith based)
friend
Usage: ἑταῖρος, -ου, ὁ [in LXX chiefly for רֵעַ and cognate forms, also Sir.11:6 37:2 ff., al. ;] a companion, comrade: Mat.11:16 (WH, ἑτέροις); voc., as term of address, my friend: Mat.20:13 22:12 26:50.† (AS)