Inappropriate, a.
Not instrument (to); not appropriate; unbecoming; unsuitable; not specially fitted; -- followed by to or for. -- In`ap*pro"pri*ate*ly, adv. -- In`ap*pro"pri*ate*ness, n.
Shades of meaning
Fernald has no entry of its own for inappropriate; he lists it under alien, incongruous.
Where he writes about it:
Impertinent and irrelevant matters can not claim consideration in a certain connection; inappropriate matters could not properly be considered. — from alien