1. research

systematic investigation to establish facts

2. enquiry, inquiry, research

a search for knowledge

Example Sentences:
'their pottery deserves more research than it has received'

• enquiry
• inquiry

3. research

attempt to find out in a systematically and scientific manner

Example Sentences:
'The student researched the history of that word'

4. explore, research, search

inquire into

Example Sentences:
'the students had to research the history of the Second World War for their history project'
'He searched for information on his relatives on the web'
'Scientists are exploring the nature of consciousness'

• explore
• search