chiefly

adv

1. (focus)Especially or primarily; above all.

   “Their relationship is chiefly professional.”

   “This is a term chiefly used by online gamers.”

   “But questions presisted^([sic]), chiefly because of the acknowledged and continuing Federal investigation of Mr. Mandel's wealthy friends, W. Dale Hess and Harry W. Rogers 3d, who have profited from business with the state.”

2. (focus)Mainly or principally; almost entirely.

adj

1. Of or relating to a chief.

   “The maintenance of a perpetual fire came to be associated with chiefly or royal dignity.”