There are many synonyms for male genitals, some of which are more appropriate and commonly used than others. Terms like penis, shaft, and member are fairly common and considered socially acceptable. Other slang terms like cock, dick, and boner may be more taboo and are generally not used in polite conversation. Some less common and more medical terms include phallus and organ. Additionally, there are many regional and cultural variations of slang terms used to refer to male genitals. It's important to use appropriate language in different situations, and to always be respectful of others.