Hair or Toenail That Pierces the Skin

This page is the CodyCross answer for the clue below from Architectural Styles, Group 1177, Puzzle 5 (Buckingham Palace).

Question is: Hair or Toenail That Pierces the Skin

and the answer is: INGROWN

Word Meaning:

INGROWN — That has grown inwards or abnormally towards (a part of the body)

Definitions from Wiktionary.