The term 'sternly disciplined' can be summed up with the crossword solution 'SPARTAN'. This word is derived from the ancient Greek city-state of Sparta, which was known for its strict military training and discipline. The Spartans were renowned for their courage and strength in battle, and their adherence to a strict code of conduct. As such, the term 'SPARTAN' has come to mean someone who is sternly disciplined and follows a strict code of conduct.