(1):

(n.) A small cluster of stars.

(2):

(n.) An optical property of some crystals which exhibit a star-shaped by reflected light, as star sapphire, or by transmitted light, as some mica.

(3):

(n.) A constellation.

(4):

(n.) Three asterisks placed in this manner, /, to direct attention to a particular passage.

(5):

(n.) An asterisk, or mark of reference.