I.  hor‧i‧zon‧tal1 /ˌhɒrəˈzɒntl◂, ˌhɒrɪˈzɒntl◂ $ ˌhɑːrəˈzɑːntl◂/ 
 adjective flat and level: 
 a horizontal surface—horizontally adverb
 a horizontal surface—horizontally adverb ⇒ 
diagonal, 
vertical [TahlilGaran] Dictionary of Contemporary English ▲
 amount how much of something there is: 
 Try to reduce the amount of fat in your diet.
 Try to reduce the amount of fat in your diet.  a tiny amount of poisonquantity
 a tiny amount of poisonquantity a particular amount of food, liquid, or another substance that can be measured – used especially in written descriptions and instructions: 
 Make sure that you add the right quantity of milk.
 Make sure that you add the right quantity of milk.  They buy the wood in large quantities.volume
 They buy the wood in large quantities.volume the amount of something such as business activity or traffic, especially when this is large or increasing: 
 The volume of traffic on our roads has risen sharply.
 The volume of traffic on our roads has risen sharply.  the huge volume of trade with Chinalevel
 the huge volume of trade with Chinalevel the exact amount of something at one time, which can go up or down at other times: 
 They measured the level of alcohol in his blood.
 They measured the level of alcohol in his blood.  There is a high level of unemployment.proportion
 There is a high level of unemployment.proportion the amount of something, compared with the whole amount that exists: 
 the proportion of road accidents caused by drunk drivers
 the proportion of road accidents caused by drunk drivers  A high proportion of the students were from poor families.quota
 A high proportion of the students were from poor families.quota a maximum amount of something that can be produced, sold, brought into a country etc: 
 import quotas on Japanese carsyield
 import quotas on Japanese carsyield /jiːld/ the amount of something that is produced, especially crops: 
 this year’s cotton yieldflat
 this year’s cotton yieldflat on one level, without any holes or raised areas, and not sloping or curving: 
 a flat roof
 a flat roof  a flat screen
 a flat screen  Before you lay the tiles, make sure that the ground is completely flat.smooth
 Before you lay the tiles, make sure that the ground is completely flat.smooth without any holes or raised areas – used especially when saying how something feels when you touch it: 
 her lovely smooth skin
 her lovely smooth skin  I ran my hand across the animal’s smooth fur.even
 I ran my hand across the animal’s smooth fur.even without any holes or raised areas: 
 Apply the paint to an even surface.
 Apply the paint to an even surface.  Be careful – the path is not very even here.horizontal
 Be careful – the path is not very even here.horizontal going straight across and not sloping: 
 a horizontal line
 a horizontal line  Raise both arms to a horizontal position.
 Raise both arms to a horizontal position. [TahlilGaran] English Thesaurus ▲