Strenuous(adjective)
(Requiring or using great effort or exertion.)
Hindi meaning:महान प्रयास करने की आवश्यकता होना
Synonyms: Arduous, Difficult, Hard, Taxing, Laborious, Toilsome, Exhausting
Antonyms: Easy, Effortless, Half-Hearted, Feeble, Facile
Example: Writing a novel under a tight deadline is a very strenuous task.
Trick to remember: Ache straight drive ke liye strenuous effort lagane padhte hai 
