Duration refers to the length of time during which something lasts or continues. However, there are several synonyms for the word duration that can be used in different contexts, depending on the type of activity or event being referred to. Some examples of synonyms for duration include span, length, and timeframe. Other related words include tenure, term, and period, which also convey the idea of a defined length of time. Additionally, words such as stretch, continuance, and persistence suggest a longer or more enduring period of time. Ultimately, the choice of synonym depends on the context in which the word is used and the specific connotations that are desired.