The phrase "got on horn" means to make a phone call. However, there are many other synonyms that can be used instead of this phrase. For example, someone can say "picked up the phone" or "dialed a number." Another option is to use "rang someone" or "called someone up." Other common phrases include "phoned," "reached out," "made a call," or "got in touch." Additionally, people may use slang terms such as "hit up" or "buzzed someone" to describe making a phone call. Regardless of the terminology used, the intention is the same - to communicate with someone over the phone.