Some historians were duly acknowledged (8)
I believe the answer is:
answered
'acknowledged' is the definition.
The answer and definition can be both related to thinking as well as being past participle verbs.
Maybe they are linked in a way I don't understand?
'some historians were duly' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'ANSWERED' is hidden within 'historians were duly'.
Can you help me to learn more?
(Other definitions for answered that I've seen before include "Rejoined" , "Replied or responded" , "Sawn reed (anag.)" , "was sufficient" , "Fulfilled" .)