add on

To include something extra, especially a charge in a total price.

• They add on tax at checkout.
• The restaurant added ten pounds on to the bill.
• Can we add on another night at the hotel?

How to use it: add something on (They added a delivery fee on.); add something on to something (The hotel added a service charge on to our bill.)

Similar words: add, include

Opposites: subtract, remove

Common phrases: add on tax, add on a fee, add on something extra

To build an extra room or section attached to an existing building.

• We want to add on a garage.
• They added on a kitchen last year.
• Could you add a room on to this house?

How to use it: add something on to a building (They added a bedroom on to the house.); add on to a building (We plan to add on to our cottage.)

Similar words: extend, build on

Common phrases: add on a room, add on a garage