The word "好玩儿" is formed by first combining the character "好" (meaning "good") with "玩" (meaning "to play" or "fun") to create the compound "好玩", which means "fun" or "interesting". The character "儿" is then appended as a retroflex suffix, a phonetic addition common in colloquial Mandarin that modifies the pronunciation to convey a casual, informal, or affectionate tone without altering the core meaning.