"sheer endeavour" is a correct and usable phrase in written English.
It can be used to describe a strong and determined effort or attempt to achieve something. Here is an example sentence: Despite facing numerous challenges, the team succeeded in their project through sheer endeavour and determination.
Mary Lyon was born into an era of inequality for women in the work place – yet through sheer endeavour she went on to become one of the foremost geneticists of the 20th century.
Exhilarating and exhausting in equal measure – and that just for those watching – England and Australia slugged it out on a day that had been expected to produce runs and instead saw the home side's batting succumb to the sheer endeavour of Peter Siddle, who took five for 50, and then the Australians stumble against the new ball.
"I thought, for sheer endeavour and determination, we thoroughly deserved the three points," he said.
That is the belief that intelligence, ability and human potential are rigidly fixed and unaffected by family income, parental support or sheer personal endeavour.
But the sheer size of the endeavour brings two linked worries to mind.
And in the seasons ahead, his uncluttered endeavour and sheer stamina repeatedly gave England hope of swaying the balance of the match.
This project exceeded previous mathematical endeavours by its sheer size, in both length of proof and number of researchers.
As much as this outcome ought to be framed by the endeavour and toil of Falkirk and their sheer bloody mindedness, this felt unerringly like a moment of self-imposed calamity for Hibs.
As Foster wrote at the time: "The sheer visual delight of the cladding details on the bank could not have happened without a shared endeavour, enthusiasm and dedication which extended from a factory in Missouri, through to a Chinese workforce on site, and a highly mobile design team who were as much at home on the shop floor as on the drawing board.
Sheer fear, sheer terror.
