Mounce Concise Greek-English Dictionary

the neck, Mt. 18:6; Mk. 9:42; Lk. 15:20; 17:2; ἐπιθεῖναι ζυγὸν ἐπὶ τὸν τράχηλον, to put a yoke upon the neck of someone, met. to bind to a burdensome observance, Acts 15:10; 20:37; ὑποτιθέναι τὸν τράχηλον, to lay down one’s neck under the axe of the executioner, to imperil one’s life, Rom. 16:4*

Source: Mounce Concise Greek-English Dictionary