studious

Concise Oxford English Dictionary © 2008 Oxford University Press:
studious/ˈstjuːdiəs/

▶adjective

• 1 spending a lot of time studying or reading.

• 2 done deliberately or with great care.

– derivatives
studiously adverb,
studiousness noun.

– origin ME: from L. studiosus, from studium ‘painstaking application’.