to unite or join so as to increase the number, quantity, size, or importance: to add two cups of sugar; to add a postscript to her letter; to add insult to injury.
to find the sum of (often fol. by up): Add this column of figures. Add up the grocery bills.
to say or write further.
to include (usually fol. by in): Don't forget to add in the tip.
—v.i.
to perform the arithmetic operation of addition: children learning to add and subtract.
to be or serve as an addition (usually fol. by to): His illness added to the family's troubles.
These figures don't add up right.
to make the desired, expected, or correct total:These figures don't add up right.
to seem reasonable or consistent; be in harmony or accord:Some aspects of the story didn't add up.
to signify; indicate: The evidence adds up to a case of murder.