A combining form is made up of a

A combining form is made up of a root word and a prefix or suffix. It is used to form new words in English. The root word gives the main meaning of the new word and the prefix or suffix adds an additional meaning. For example, the word 'unhappiness' is made up of the root word 'happy', the prefix 'un-' (meaning 'not') and the suffix '-ness' (indicating a state or condition).