Historic family's contribution to medicine (6)
I believe the answer is:
medici
'historic family's' is the definition.
'medici' can be an answer for 'family's' (I have seen 'Italian family' mean 'medici' so perhaps 'family' could also mean 'medici'). I'm not sure about the 'historic' bit.
'contribution to medicine' is the wordplay.
'contribution' becomes 'ici' (I can't justify this - if you can you should give a lot more credence to this answer).
'to' means one lot of letters go next to another (I've seen this in other clues).
'medicine' becomes 'med' (as in the informal term 'meds').
'ici' put after 'med' is 'MEDICI'.
Can you help me to learn more?
(Other definitions for medici that I've seen before include "Prominent family of Florence" , "Florentine ruler" , "Noble Florentine family" , "Powerful 15th-century family of bankers and merchants in Florence" , "Name of powerful Italian family in 15th-17th centuries" .)