Ridiculed James, the first from Spain to order deer (6)
I believe the answer is:
Here is my best explanation:
'ridiculed' is the definition.
The definition and answer can be both to do with communicating as well as being past participle verbs.
Perhaps you can see a link between them that I don't see?
'james the first from spain to order deer' is the subsidiary indication.
'the first' suggests taking the first letters.
'from' says to put letters next to each other.
'spain' becomes 'e' (abbreviation for Espana**).
'to order' indicates anagramming the letters.
The initial letter of 'james' is 'j'.
'deer' with letters rearranged gives 'ered'.
(Other definitions for jeered that I've seen before include "Ridiculed, sneered", "Ridiculed, scorned", "Did deride", "Mocked, derided", "Barracked" and "Laughed with derision".)