Definition of hair noun from the Oxford Advanced Learner's Dictionary

Oxford3000

hair

noun
heə(r)
 
; her
 
 
1 [uncountable, countable] the substance that looks like a mass of fine threads growing especially on the head; one of these threads growing on the body of people and some animalsfair/dark hairstraight/curly/wavy hairto comb/brush your hairShe often wears her hair loose. (informal) I'll be down in a minute. I'm doing(= brushing, arranging, etc.)my hair.I'm having my hair cut this afternoon.He's losing his hair (= becoming bald ).body/facial/pubic hairThere's a hair in my soup.The rug was covered with cat hairs. see also camel hair, horsehair2 -haired (in adjectives) having the type of hair mentioneddark-hairedlong-haired3 [countable] a thing that looks like a fine thread growing on the leaves and stems of some plants
Idioms

get in somebody's hair

(informal) to annoy somebody by always being near them, asking them questions, etc.

the hair of the dog (that bit you)

(informal) alcohol that you drink in order to make you feel better when you have drunk too much alcohol the night before

keep your hair on

(British English, informal) used to tell somebody to stop shouting and become calm when they are angry

let your hair down

(informal) to relax and enjoy yourself, especially in a lively wayIt's about time you let your hair down and had some fun!

make somebody's hair stand on end

to shock or frighten somebody
a chilling tale that will make your hair stand on end

not harm/touch a hair of somebody's head

to not hurt somebody physically in any way

not have a hair out of place

(of a person) to look extremely clean and neat

not turn a hair

to show no emotion when something surprising, shocking, etc. happens
She listened to his confession without turning a hair.
more at hang by a hair/thread at hang v., not see hide nor hair of somebody/something at hide n., split hairs at split v.
Idioms
see
tear your hair out at tear1 v.
Usage noteUsage note: Clothes and fashionClothesbe wearing a new outfit/bright colours/fancy dress/fur/uniformbe (dressed) in black/red/jeans and a T-shirt/your best suit/leather/silk/rags (= very old torn clothes)be dressed for work/school/dinner/a special occasionbe dressed as a man/woman/clown/piratewear/dress in casual/designer/second-hand clotheswear jewellery/(especially US) jewelry/accessories/a watch/glasses/contact lenses/perfumehave a cowboy hat/red dress/blue suit onput on/take off your clothes/coat/shoes/helmetpull on/pull off your coat/gloves/sockschange into/get changed into a pair of jeans/your pyjamas/(especially US) your pajamasAppearancechange/enhance/improve your appearancecreate/get/have/give something a new/contemporary/retro lookbrush/comb/shampoo/wash/blow-dry your hairhave/get a haircut/your hair cut/a new hairstylehave/get a piercing/your nose piercedhave/get a tattoo/a tattoo done (on your arm)/a tattoo removedhave/get a makeover/cosmetic surgeryuse/wear/apply/put on make-up/cosmeticsFashionfollow/keep up with (the) fashion/the latest fashionsspend/waste money on designer clothesbe fashionably/stylishly/well dressedhave good/great/terrible/awful taste in clothesupdate/revamp your wardrobebe in/come into/go out of fashionbe (back/very much) in voguecreate a style/trend/vogue for somethingorganize/put on a fashion showshow/unveil a designer's spring/summer collectionsashay/strut down the catwalk/(North American English also) runwaybe on/do a photo/fashion shootUsage noteUsage note: Physical appearanceA person may be described as having:Eyes(bright) blue/green/(dark/light) brown/hazel eyesdeep-set/sunken/bulging/protruding eyessmall/beady/sparkling/twinkling/(informal) shifty eyespiercing/penetrating/steely eyesbloodshot/watery/puffy eyesbushy/thick/dark/raised/arched eyebrowslong/dark/thick/curly/false eyelashes/lashesFacea flat/bulbous/pointed/sharp/snub nosea straight/a hooked/a Roman/(formal) an aquiline nosefull/thick/thin/pouty lipsdry/chapped/cracked lipsflushed/rosy/red/ruddy/pale cheekssoft/chubby/sunken cheekswhite/perfect/crooked/protruding teetha large/high/broad/wide/sloping foreheada strong/weak/pointed/double china long/full/bushy/wispy/goatee bearda long/thin/bushy/droopy/handlebar/pencil moustache/(especially US) mustacheHair and skinpale/fair/olive/dark/tanned skindry/oily/smooth/rough/leathery/wrinkled skina dark/pale/light/sallow/ruddy/olive/swarthy/clear complexiondeep/fine/little/facial wrinklesblonde/blond/fair/(light/dark) brown/(jet-)black/auburn/red/(British English) ginger/grey hairstraight/curly/wavy/frizzy/spiky hairthick/thin/fine/bushy/thinning hairdyed/bleached/soft/silky/dry/greasy/shiny hairlong/short/shoulder-length/cropped haira bald/balding/shaved heada receding hairlinea bald patch/spota side/centre/(US) center (British English) parting/(North American English) partBodya long/short/thick/slender/(disapproving) scrawny neckbroad/narrow/sloping/rounded/hunched shouldersa bare/broad/muscular/small/large chesta flat/swollen/bulging stomacha small/tiny/narrow/slim/slender/28-inch waistbig/wide/narrow/slim hipsa straight/bent/arched/broad/hairy backthin/slender/muscular armsbig/large/small/manicured/calloused/gloved handslong/short/fat/slender/delicate/bony fingerslong/muscular/hairy/shapely/(both informal, often disapproving) skinny/spindly legsmuscular/chubby/(informal, disapproving) flabby thighsbig/little/small/dainty/wide/narrow/bare feeta good/a slim/a slender/an hourglass figurebe of slim/medium/average/large/athletic/stocky build