supplementary

From Wiktionary
supplementary is on the Academic Word List.

Word parts[change]

supplement + -ary

Adjective[change]

Positive
supplementary

Comparative
more supplementary

Superlative
most supplementary

  1. If something is supplementary, it is added on; it is not needed, but it is often useful.
    Many immigrants are employed but also feel the need to seek supplementary income.
    These software solutions are more supplementary than basic.

Related words[change]