ἴχνος/ichnos

This word is a type of thing. It is a noun.

This word can mean track or footstep. A track or footstep is the imprint left behind when a person or an animal walks across the ground.
This word can mean something that is like a track or footstep in some way.

See: Romans 4:12; 2 Corinthians 12:18; 1 Peter 2:21