Add and Tag on

Add verb - To join (something) to a mass, quantity, or number so as to bring about an overall increase.

Tag on and add are semantically related in tack on topic. In some cases you can use "Tag on" instead a verb "Add". informal substitute

Nearby Words: added, adding

Tag on verb - Fix to; attach.

Add and tag on are semantically related in attach topic. You can use "Add" instead a verb "Tag on", if it concerns topics such as unite, join, attach or stick.