hair extension vs mane

hair extension

noun
  • A length of hair which is attached to one's normal hair to make it longer. 

mane

noun
  • Long or thick hair of a person's head. 

  • Longer hair growth on back of neck of an animal, especially a horse or lion 

  • Part of a naval sword between the tang button and the quillon. 

How often have the words hair extension and mane occurred in a corpus of books? (source: Google Ngram Viewer )