1 Answer

re·search   [ri-surch, ree-surch] 
noun
1.
diligent and systematic inquiry or investigation into a subject in order to discover or revise facts, theories, applications, etc.: recent research in medicine.
2.
a particular instance or piece of research.
verb (used without object)
3.
to make researches; investigate carefully.
verb (used with object)
4.
to make an extensive investigation into: to research a matter thoroughly.
Origin:
1570–80; (v.) < Middle French recercher to seek, Old French, equivalent to re- re- + cercher to search; (noun) < Middle French recerche

Related forms
re·search·a·ble, adjective
re·search·er, re·search·ist, noun
pro·re·search, adjective
un·der·re·search, verb (used with object)