Royal meeting disorganised group of soldiers (8)
I believe the answer is:
regiment
'group of soldiers' is the definition.
'regiment' can be an answer for 'soldiers'. I'm unsure of the 'group of' bit.
'royal meeting disorganised' is the wordplay.
'royal' becomes 'r' (abbreviation).
'disorganised' is an anagram indicator.
'meeting' anagrammed gives 'egiment'.
'r'+'egiment'='REGIMENT'
Can you help me to learn more?
(Other definitions for regiment that I've seen before include "Organise; army unit" , "a whole lot of them" , "Force under colonel" , "Large army unit" , "Military unit" .)