"Instance" is a useful word to convey the occurrence of a specific event or situation. However, there are several synonyms that can be used in its place to provide more variety in writing and speaking. One alternative is "case," which refers to a specific example or occurrence of something. Another option is "occurrence," which emphasizes the happening or taking place of an event. "Example" can also be used in place of instance to describe a specific situation or case. "Event," "situation," and "circumstance" are three more alternatives that can be used in place of instance to convey a similar meaning.