Scientific study of blood overlooking blood group in clusters (11)
I believe the answer is:
mathematics
'scientific study' is the definition.
'mathematics' can be an answer for 'study' (mathematics is a kind of study). I'm not sure about the 'scientific' bit.
'of blood overlooking blood group in clusters' is the wordplay.
I cannot quite understand how this works, but
'blood group' could be 'a' (A is one of the main blood groups) and 'a' is found in the answer.
'of blood' could be 'hematic' (I've seen this in another clue) and 'hematic' is found within the answer.
The remaining letters 'mts' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for mathematics that I've seen before include "a school subject" , "In which pupils may have to add" , "The science of numbers etc" , "Numerical science" , "Sums" .)