Definitions

1. adjective

Having more hair than something or someone else; having a more luxuriant or abundant growth of hair

“She thought he looked hairier than his brother, even though they both had beards.”

2. comparative

Comparing two things, with the one described as hairier being the one with more hair

“The jungle was hairier than the savannah.”

3. superlative

Describing the thing with the most hair compared to other things

“The Himalayas are the hairiest mountains in the world.”