There are several synonyms for the phrase "choke on". One alternative would be to use "gag on", which has a similar meaning of having difficulty swallowing or breathing. Another option could be to say "struggle to swallow" or "have a hard time ingesting". Additionally, "suffocate on" could be used to describe a situation where the airway is completely blocked, leading to potentially serious breathing problems. Essentially, any phrase that conveys difficulty in breathing or swallowing could be used as a synonym for "choke on", as long as the context in which it's being used is clear.