Adjective

(er)

Having length; long and overextended, especially in time rather than dimension.

*{{quote-news

, year=2011 , date=Jluy 19 , author=Ella Davies , title=Sticks insects survive one million years without sex , work=BBC citation , page= , passage=They traced the ancient lineages of two species to reveal the insects' lengthy history of asexual reproduction. }}

a lengthy text

a lengthy discussion

a laborious and lengthy process

She died last night after a lengthy illness.

They received lengthy prison terms.

Adjective

(en adjective)

imposing]] or [[constitute, constituting a physical, mental, or figurative load which can be borne only with effort.

* 1820 , , "The Legend of Sleepy Hollow":

That all this might not be too onerous on the purses of his rustic patrons, who are apt to consider the costs of schooling a grievous burden, and schoolmasters as mere drones, he had various ways of rendering himself both useful and agreeable.

* 1848 , , Shirley , ch. 13:

Again, and more intensely than ever, she desired a fixed occupation,—no matter how onerous , how irksome.

* 1910 , , "The Golden Poppy" in Revolution and Other Essays :

[I]t has become an onerous duty, a wearisome and distasteful task.