A.T. Robertson Commentary Titus 1:10

"For there are many unruly men, vain talkers and deceivers, specially they of the circumcision," — Titus 1:10 (ASV)

Vain talkers (ματαιολογο). Late and rare compound, empty talkers, in Vett. Val. and here. See 1 Timothy 1:6 for ματαιολογια.

Deceivers (φρεναπατα). Late and rare compound, in papyri, eccl. writers, here alone in N.T. "Mind-deceivers." See Ga 6:3 for φρεναπαταιν.

Specially they of the circumcision (μαλιστα ο εκ της περιτομης). Same phrase in Ac 11:2; Galatians 2:12; Colossians 4:11. Jews are mentioned in Crete in Ac 2:11. Apparently Jewish Christians of the Pharisaic type tinged with Gnosticism.