American specialised soldier regularly leads (7)
I believe the answer is:
majored
'american' is the definition.
The answer and definition are not the same part of speech. However, past participle verbs and adjectives sometimes mean the same thing.
'specialised soldier regularly leads' is the wordplay.
'specialised' becomes 'maj' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'soldier' becomes 'OR' (soldier from Other Ranks).
'regularly' indicates alternate letters (regularly take one letter, leave next etc.).
The alternate letters of 'leads' are 'ed'.
'maj'+'or'+'ed'='MAJORED'
Can you help me to learn more?
(Other definitions for majored that I've seen before include "Specialised in a particular subject" , "specialized" .)