At, or in contact with, the surface or
upper part of a thing, and supported by it; placed or lying in
contact with the surface; as, the book lies on the table,
which stands on the floor of a house on an
island.
To or against the surface of; -- used to
indicate the motion of a thing as coming or falling to the surface of
another; as, rain falls on the earth.
Denoting performance or action by contact
with the surface, upper part, or outside of anything; hence, by means
of; with; as, to play on a violin or piano. Hence,
figuratively, to work on one's feelings; to make an impression
on the mind.
At or near; adjacent to; -- indicating
situation, place, or position; as, on the one hand, on
the other hand; the fleet is on the American coast.
In addition to; besides; -- indicating
multiplication or succession in a series; as, heaps on heaps;
mischief on mischief; loss on loss; thought on
thought.
Indicating dependence or reliance; with
confidence in; as, to depend on a person for assistance; to
rely on; hence, indicating the ground or support of anything;
as, he will promise on certain conditions; to bet on a
horse.
At or in the time of; during; as,
on Sunday we abstain from labor. See At
(synonym).
At the time of, conveying some notion of
cause or motive; as, on public occasions, the officers appear
in full dress or uniform. Hence, in consequence of, or following; as,
on the ratification of the treaty, the armies were
disbanded.
Toward; for; -- indicating the object of
some passion; as, have pity or compassion on him.
At the peril of, or for the safety
of.
By virtue of; with the pledge of; --
denoting a pledge or engagement, and put before the thing pledged;
as, he affirmed or promised on his word, or on his
honor.
To the account of; -- denoting
imprecation or invocation, or coming to, falling, or resting upon;
as, on us be all the blame; a curse on him.
In reference or relation to; as,
on our part expect punctuality; a satire on
society.
Of.
Occupied with; in the performance of; as,
only three officers are on duty; on a
journey.
In the service of; connected with; of the
number of; as, he is on a newspaper; on a
committee.
In celebration of Noah Webster's Birthday (October 16, 2009), we have prepared an updated website. 
