Abbott-Smith Manual Greek Lexicon
καίτοι (G2543)
2 ** καίτοι (= καί τοι , and so also written in cl.), concessive particle, [in LXX: IV Mac 2:6 *;] and yet , although : Ac 14:17 ; c. ptcp., He 4:3 .†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain