adjective

1. not easily dented, pierced, cut, or crushed; resistant to pressure; firm and unyielding to the touch; rigid; solid and compact
2. having firm muscles; in good bodily trim; vigorous and robust
3. showing, or done with, great force or strength; powerful; violent; vigorous a hard blow
4. demanding great physical or mental effort or labor; fatiguing; difficult; specif.,
   1. difficult to do hard work
   2. difficult to understand, explain, or answer a hard question
   3. difficult to deal with; not easily managed or controlled a man hard to live with
   4. firmly fastened or tied a hard knot
5. 1. not easily moved; unfeeling; callous a hard heart
   2. unfriendly; hostile hard feelings
6. practical and shrewd or calculating a hard customer
7. 1. firm or definite, esp. in an aggressive way a hard line in foreign policy
   2. undeniable, reliable, or actual hard facts
   3. consisting of the basic facts about major events, as opposed to presenting feature stories, opinion, etc. hard news
8. causing pain or discomfort; specif.,
   1. difficult to endure; trying; exhausting a hard life
   2. harsh; severe; stern a hard master, hard words
9. very cold, stormy, etc.; inclement a hard winter
10. 1. harsh, stiff, and wiry: said of fibers or cotton
    2. having no nap: said of a finish for fabric
    3. having a texture that is firm, dense, wiry, etc. a dog with a hard coat
11. 1. clearly defined or having sharp contrast; distinct hard outlines
    2. too clear, bright, or penetrating to be pleasant a hard light
12. having in solution mineral salts that interfere with the lathering and cleansing properties of soap, corrode metals, etc.: said of water
13. energetic and persistent; steady and earnest a hard worker
14. 1. fermented; alcoholic hard cider
    2. containing a relatively high percentage of alcohol; strong hard liquor
15. : said of money
    1. of metal, not paper
    2. of currency or coin, not credit
16. : said of certain currencies
    1. that can be exchanged for gold or silver
    2. that is readily accepted as foreign exchange
17. Phonet.: not used in these ways as a technical term by phoneticians
    1. designating c sounded as in can or g sounded as in gun a hard g
    2. voiceless, as the sound of s in sin
    3. not palatalized: said as of certain consonants in Slavic languages
18. Agric. high in gluten content hard wheat
19. Chem. not easily biodegradable: said of detergents and pesticides
20. Commerce high and stable: said of a market, prices, etc.
21. Mil. heavily fortified: said as of an underground installation a hard base
22. Radiology of high penetrating power: said of X-rays

Etymology: ME < OE heard, akin to Ger hart < IE base *kar-, hard > Gr karyon, nut, kratos, strength

adverb

1. energetically and persistently; steadily and earnestly work hard
2. with strength, violence, or severity hit hard
3. with difficulty: often used in hyphenated compounds hard-earned, hard-sought
4. so as to withstand much wear, use, etc. hard-wearing clothes
5. deeply; fully; soundly sleep hard
6. firmly; tightly hold on hard
7. close; near we live hard by the woods
8. so as to be or make firm, solid, or rigid to freeze hard
9. with vigor and to the fullest extent: used esp. in indicating direction hard alee! turn hard right