Long in the tooth is an idiomatic expression, which is used to describe someone who is getting older or aged. However, this phrase has developed some negative connotations and considered disrespectful, especially when referring to a person. Therefore, some alternatives might include "senior," "mature," "seasoned," "experienced," and "veteran." These words are less objectionable and more positive alternatives, and they don't have any age-ist overtones. Additionally, euphemistic expressions like "full of life experience," "a well-travelled path," and "Aged like fine wine," can also substitute for the phrase "long in the tooth." Choosing the right word or phrase can help you avoid unintended emotions or conflict.