verb To join or unite (e.g. one thing to another, or as several particulars) so as to increase the number, augment the quantity, or enlarge the magnitude, or so as to form into one aggregate.
verb To sum up; to put together mentally; to add up.
to add numbers
verb To combine elements of (something) into one quantity.
to add a column of numbers
verb To give by way of increased possession (to someone); to bestow (on).
verb To append (e.g. a statement); to say further information.
verb To intensify; to augment; to increase.
It adds to our anxiety.
verb To perform the arithmetical operation of addition.