Definitions

1. adjective

having or showing a serious and unyielding attitude or expression; strict and unyielding in one’s rules or expectations

“The stern teacher kept a close eye on the misbehaving students.”

2. noun

the back or rear part of a ship

“The stern of the ship was damaged in the storm.”

3. verb

to make or become stern, especially in one’s attitude or expression

“After the argument, she tried to stern herself and not let her emotions get the better of her.”