Old geezer is a term used to refer to an older man, typically one who is no longer in his prime. However, this term is often considered derogatory and disrespectful. There are many synonyms that can be used to describe an older man without causing offense. Some of these synonyms include senior citizen, elder, veteran, patriarch, sage, statesman, seasoned citizen, and greybeard. These terms emphasize the wisdom and experience that come with age, rather than focusing on physical or mental decline. It's important to choose the right words when describing people and to treat everyone with respect and dignity, regardless of their age.