The phrase "are big about" has a positive connotation, implying that someone is enthusiastic or passionate about something. However, there are several antonyms that convey negative or neutral meanings. Words like indifferent, dispassionate, apathetic, unenthusiastic, and lackadaisical suggest a lack of interest or concern. Other antonyms include unimpressed, unexcited, unconcerned, and bored. These words denote a lack of engagement or emotional investment in a particular topic, activity, or event. While being "big about" something can be a positive attribute, it's equally important to recognize that not everyone feels the same level of enthusiasm or excitement about everything.