Abbott-Smith Manual Greek Lexicon
ἴχνος (G2487)
3 ἴχνος , -εος (-ους), τό , [in LXX for כַּף , etc.;] a track , footstep : metaph. (as freq. in cl.), στοιχεῖν τοῖς ἴ. , Ro 4:12 ; περιπατεῖν τοῖς ἴ. , II Co 12:18 ; ἐπακολουθεῖν τοῖς ἴ. , I Pe 2:21 (cf. MM, Exp. , xv).†
G. Abbott-Smith, A Manual Greek Lexicon of the New Testament (1922) — public domain