add on

verbs

make an addition
"Let's add on to this"
add on
is derived from
add-on
is a type of (narrower)
make an addition (to); join or combine or unite with others; increase the quality, quantity, size or scope of
"We added two students to that dorm room"; "She added a personal note to her letter"; "Add insult to injury"; "Add some extra plates to the dinner table"
add
add to the very end
"He appended a glossary to his novel where he used an invented language"
add on, affix, append, supplement
is derived from
add-on