Noun

(uncountable) Diligent inquiry or examination to seek or revise facts, principles, theories, applications, etc.; laborious or continued search after truth.

* {{quote-magazine, date=2012-01

, author=Philip E. Mirowski , title=Harms to Health from the Pursuit of Profits , volume=100, issue=1, page=87 , magazine= citation , passage=In an era when political leaders promise deliverance from decline through America’s purported preeminence in scientific research , the news that science is in deep trouble in the United States has been as unwelcome as a diagnosis of leukemia following the loss of health insurance.}}

(countable) A particular instance or piece of research.

* Macaulay

The dearest interests of parties have frequently been staked on the results of the researches of antiquaries.

* 1747 , The Scots magazine (volume 9, page 567)

The first step I took in this so necessary a research , was to examine the motives, the justice, the necessity and expediency of the revolution