hide (n)or hair
No sign or sight of something or someone. I haven't seen hide nor hair of our neighbor in weeks—I hope he's OK! Can you go check outside for the cat? I haven't seen hide or hair of her in hours.
hide or hair
No trace or evidence of someone or something. I haven't seen hide or hair of Mary since this morning.
*(neither) hide nor hair
Cliché no sign or indication of someone or something. (*Typically: find ~; see ~.) We could find neither hide nor hair of him. I don't know where he is. There has been no one here. We found neither hide nor hair.
hide nor hair
A trace; a vestige: haven't seen hide nor hair of them since the argument.