Insubordinate, a.
Not submitting to authority; disobedient; rebellious; mutinous
Shades of meaning
Fernald has no entry of its own for insubordinate; he lists it under rebellious.
Where he writes about it:
Insubordinate applies to the disposition to resist and resent control as such; mutinous, to open defiance of authority, especially in the army, navy, or merchant marine. — from rebellious