Decimal system absurdly claimed to be clinical (7)
I believe the answer is:
medical
'to be clinical' is the definition.
(thesaurus)
'decimal system' is the wordplay.
'system' indicates anagramming the letters (another version or system with the same letters).
'decimal' with letters rearranged gives 'MEDICAL'.
'absurdly claimed' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for medical that I've seen before include "Claimed (anag.)" , "Health check-up" , "examination carried out by a doctor" , "Of the science dealing with treatment of disease" , "Relating to treatment rather than surgery" .)