• natral father,
• batural father,
• matural father,
• jatural father,
• hatural father,
• nztural father,
• nstural father,
• nwtural father,
• nqtural father,
• narural father,
• nafural father,
• nagural father,
• nayural father,
• na6ural father,
• na5ural father,
• natyral father,
• nathral father,
• natjral father,
• natiral father,
• nat8ral father

The adjective form of "natural father" is "biological".

The plural form of "natural father" is "natural fathers"

The singular form of the word "natural father" is "natural father".