Being very important, or key to something.
Having or containing the centre of something.
Being in the centre.
Exerting its action towards the peripheral organs.
centre
Pertaining to or dependent on circumstances, especially as opposed to essentials; incidental, not essential.
Suggesting guilt, but not proving it conclusively.
Abounding with minor circumstances; in great detail; particular.
Full of circumstance or pomp; ceremonial.
Something incidental to the main subject, but of less importance.