Teener is a slang term to describe a teenager, particularly someone in their later teen years. Some synonyms for teener include adolescent, youth, young adult, high schooler, and teen. Other similar words might include juvenile, minor, or student. Depending on the context and tone, the word used to describe a teen could have different connotations - for example, "youth" might suggest a more positive or optimistic view of young people, while "juvenile" could carry a negative or judgmental tone. Regardless, there are many words that could be used as an alternative for the term "teener".