Sign with inclusion of a thousand large groups (6)
I believe the answer is:
armies
'a thousand large groups' is the definition.
The answer and definition can be both groups as well as being plural nouns.
Maybe they are linked in a way I don't understand?
'sign with inclusion' is the wordplay.
'sign' becomes 'Aries' (star sign).
'with' means one lot of letters goes inside another.
'inclusion' becomes 'm' (I can't explain this - if you can you should believe this answer much more).
'aries' placed around 'm' is 'ARMIES'.
'of' acts as a link.
Can you help me to learn more?
(Other definitions for armies that I've seen before include "Large groups of soldiers" , "Bodies of people organised for war" , "Fighting forces" , "Organizations of military land forces" , "Hosts" .)