They are obviously not old enough to be army officers (6)
I believe the answer is:
minors
'army officers' is the definition.
The definition and answer can be both people as well as being plural nouns.
Perhaps you can see a link between them that I don't see?
'they are obviously not old enough' is the wordplay.
I cannot really see how this works, but
'not' could be 'no' (I've seen this in other clues) and 'no' is present in the answer.
The remaining letters 'mirs' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
'to be' acts as a link.
Can you help me to learn more?
(Other definitions for minors that I've seen before include "They're too young to vote" , "could be little ones" , "Young people" , "They're under-age" , "They are legally under-age" .)