Officer playfully followed by Barbara (5)

I believe the answer is:

major

I'm a little stuck... Click here to teach me more about this clue!

'officer' is the definition.
(type of military officer)

I can't explain the rest of the clue.

(Other definitions for major that I've seen before include "5,27 [PRIME MINISTER]" , "Significant, main" , "Of greater importance or stature" , "Important, significant" , "Commissioned military officer" .)

I've seen this clue in the Evening Standard.

Want a hint initially instead of a full solution? Install my app