a covering for the body (or parts of it) consisting of a dense growth of threadlike structures (as on the human head); helps to prevent heat loss
"he combed his hair"
"each hair consists of layers of dead keratinized cells"
a very small distance or space
"they escaped by a hair's-breadth"
"they lost the election by a whisker"
a filamentous projection or process on an organism
"The barnacle attached itself to the rough, hair-like projections on the crab's shell for protection."
A pigmented filament of keratin which grows from a follicle on the skin of humans and other mammals.
"She gently combed out the tangled hair that had grown over her eyebrow since childhood."
In plain English: Hair is the fine thread-like covering that grows on your head, arms, legs, and other parts of your body.
"She brushed her long hair before going out."
Usage: Use "hair" to refer to individual strands growing from your scalp or body, or collectively to describe this covering on mammals. Do not confuse it with "wool," which specifically denotes the coarse hair found on sheep and some other animals.
To remove the hair from.
"She spent an hour at the salon getting her eyebrows waxed to remove the unwanted hair between them."
In plain English: To hair something means to cover its surface with short, stiff bristles or fibers.
"She decided to get her hair cut at the local salon."
Usage: As a verb, hair means to cover a surface with short, stiff fibers or bristles rather than removing them. You would correctly use it when describing how someone applies bristles to a broom or brushes to a hat.
A surname.
"My neighbor Mr. Hair is moving to the city next week."
The word hair comes from the Old English hǣr and traces its roots back to a Proto-Indo-European term meaning "to scrape" or "comb." It entered Middle English as her before becoming the modern word we use today.