The phrase "is big on" generally relates to enthusiasm, support or interest in something. Its antonyms can be "indifferent to," "unimpressed by," "averse to," "disinclined towards," "hostile to," and "opposed to." These antonyms imply a lack of interest or disapproval towards the subject at hand. For example, if someone is big on environmental conservation, someone else can be indifferent or unimpressed by the same subject. Therefore, it is essential to understand the antonyms of "is big on" to use it correctly in context. Using the word accurately brings clarity and avoids misunderstandings in communication.