When it comes to the term "saying hello," there are various antonyms that could be relevant, depending on the context. For example, if we want to describe a situation where someone doesn't acknowledge another person's presence, we could use antonyms like ignoring, dismissing, or snubbing. Alternatively, if we are talking about an instance where someone actively avoids greeting someone else, we could use antonyms such as avoiding, evading, or eluding. Additionally, if we're talking about the manner in which someone says hello, we could use antonyms like muttering, grumbling, or growling to convey a negative tone. Overall, antonyms for "saying hello" will vary depending on the intended meaning and context of the phrase.