(1):

(n.) An heir apparent.

(2):

(a.) Capable of being seen, or easily seen; open to view; visible to the eye; within sight or view.

(3):

(a.) Clear or manifest to the understanding; plain; evident; obvious; known; palpable; indubitable.

(4):

(a.) Appearing to the eye or mind (distinguished from, but not necessarily opposed to, true or real); seeming; as the apparent motion or diameter of the sun.