A group or division of ten; esp., a period of ten years; a decennium; as, a decade of years or days; a decade of soldiers; the second decade of Livy.
20 years.
Decades is a Greak word. (δεκάδες) It means ''ten of something''. If you want to say 'ten years'' its ''decaetia'' , the prefix deca- meaning ten and -etos meaning year.
It means that it lasted that long.
4.5 decades equals 4.5 decades!
No, you don't need a hyphen. It would be 10 decades or ten decades.
Decades is correct.
100 decades in a millennium
There are 3.5 decades in 35 years
30 decades
As long as it stays cool, decades and decades and decades.
"Out" is traditionally an adverb, but in recent decades it has also been used as a verb, meaning to reveal a characteristic that has previously been hidden.
"Out" is traditionally an adverb, but in recent decades it has also been used as a verb, meaning to reveal a characteristic that has previously been hidden.