Church Times is ordered by a scientist (7)
I believe the answer is:
chemist
'a scientist' is the definition.
(chemist is a kind of scientist)
'church times is ordered by' is the wordplay.
'church' becomes 'ch' (common abbreviation).
'is ordered' indicates an anagram.
'by' says to put letters next to each other.
'times' with letters rearranged gives 'emist'.
'ch'+'emist'='CHEMIST'
(Other definitions for chemist that I've seen before include "Pharmacist, professional who dispenses drugs etc" , "Shop selling medicines" , "He dispenses prescriptions" , "Faraday, for example" , "Seller of medications" .)