Physically above and in contact with. / Physically directly supported by. / Being followed by another so as to form a series. / At (a prescribed point in time). / On.

(obsolete) by the by; incidentally

Synonym of on the books

To find or think of something unexpectedly.

To seize. / To attack.

Alternative form of upon the whole matter

Alternative form of on the carpet

Synonym of on the square

(transitive, slightly more formal) Alternative form of dwell on

Alternative form of on the point of