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.

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.

Journalism . copy added to a completed story. ?

add up to, to signify; indicate

The evidence adds up to a case of murder.

add up

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.

verb

augment , amplify , expand