Sesquicentenarian is a word used to describe someone who is 150 years old or more. However, this word is not very frequently used in everyday conversation. As such, people may choose to use alternate words or phrases to describe an individual of such an advanced age. Some synonyms for sesquicentenarian might include terms like supercentenarian, ultracentenarian, or even simply saying someone is over a century and a half old. Additionally, some people might opt to use more descriptive language, such as saying someone is in their second century of life, or describing them as having lived through multiple generations.