Number of degrees make Peter mature, oddly (11)
I believe the answer is:
temperature
'number of degrees' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'peter mature oddly' is the wordplay.
'oddly' is an anagram indicator.
'peter'+'mature'='petermature'
'petermature' anagrammed gives 'TEMPERATURE'.
'make' is the link.
Can you help me to learn more?
(Other definitions for temperature that I've seen before include "Measure of heat" , "Measure of warmth" , "Degree of heat" , "Degree of hotness" .)