They object to professional examiners (10)
I believe the answer is:
protesters
'they object' is the definition.
Although both the answer and 'object' are nouns, they are not in the same form of the noun.
'professional examiners' is the wordplay.
'professional' becomes 'pro' (abbreviation).
'examiners' becomes 'testers' ('tester' can be a synonym of 'examiner').
'pro'+'testers'='PROTESTERS'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for protesters that I've seen before include "We might be at a March" , "demonstrators" .)