Explorer died by rifle (5)
I believe the answer is:
drake
'explorer' is the definition.
(I know that Drake is a navigator)
'died by rifle' is the wordplay.
'died' becomes 'd' (abbreviation next to the year of someone's death).
'by rifle' becomes 'rake' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'd'+'rake'='DRAKE'
Can you help me to learn more?
(Other definitions for drake that I've seen before include "Navigator" , "flyer" , "Explorer" , "Male water-bird" , "First English captain to sail round the world" .)