Answer: The word 'generic' is most similar in meaning to 'common'.
Explanation: The word 'generic' is an adjective used to refer to something that is related to or typical of a group of things and not to a specific thing. Therefore, the word 'generic' is not used to make reference to a particular thing as the word 'unique' and 'specific' do. On the other hand, 'common' has a similar meaning to 'generic' since it is also used to refer to something that belongs to a group of people or things and not to a unique entity.
