The idiomatic expression "a lot of hair" means having a large amount or volume of hair. It can also imply being very particular, meticulous or fussy about something.
Sentences with «lot of hair»
These tend to be dogs with big ears that flop down or those with lots of hair in their ears. (petguide.com)
Hair loss can happen for other reasons: Babies born with lots of hair often lose it as hormone levels drop. (babycenter.com)
The finish that this gives my brows is a very soft, natural look that makes it look like I naturally have lots of hairs on my brows. (beautynerdbynight.com)