a period of 10 years

The cardinal number equal to 2 × 10, The decade from 20 to 29 in a century, The number next following nineteen; the sum of twelve and eight, or twice ten; twenty units or objects; a score, adjective denoting a quantity consisting of 20 items or units, An indefinite number more or less that twenty, One more than nineteen; twice ten

To that extent; by that much. Used before a comparative, By that; by how much; by so much; on that account; -- used before comparatives, With a comparative or more and a verb phrase, establishes a parallel with one or more other such comparatives, intransitive verb_ obsolete See thee, definite article_ Used before singular or plural nouns and noun phrases that denote particular, specified persons or things, Used to indicate uniqueness., Used before the plural form of a numeral denoting a specific decade of a century or of a lifespan

A decade or the numbers from 40 to 49, the cardinal number that is the product of ten and four, adjective_ Four times ten; thirty-nine and one more,

the cardinal number that is the product of ten and five, The sum of five tens; fifty units or objects, A decade or the numbers from 50 to 59, adjective_ being ten more than forty

Plural form of decade

A period of ten years, A group or series of ten