Stern can be defined as serious and unrelenting, especially in the assertion of authority and exercise of discipline.
It conveys a sense of severity, rigidity, and a lack of warmth or leniency. A stern demeanor can be perceived as intimidating or unyielding. Furthermore, the word can denote the rear or back part of a boat or ship, especially with a square or slightly rounded shape.
In the context of boats it is usually a noun. When referring to behavior, its usually an adjective. .
AFT ASS BUM CAN
GRIM REAR DOUR IRON HARD BACK FIRM POOP TAIL ARSE BUNS BUTT PRAT RUMP SEAT TUSH
STALK HARSH RIGID GRAVE TOUGH FANNY NATES STARK ANGRY
SEVERE STRICT FLINTY BEHIND BOTTOM
AUSTERE QUARTER HINDEND KEISTER REAREND TAILEND TOOSHIE
HARDBACK EXACTING BACKSIDE BUTTOCKS DERRIERE RIGOROUS
STRINGENT UNBENDING DRACONIAN UNSMILING DEMANDING AFTERPART FUNDAMENT POSTERIOR
UNYIELDING FORBIDDING IRONFISTED ISAACSTERN INEXORABLE RELENTLESS
HARDHEARTED UNFORGIVING UNRELENTING
HINDQUARTERS UNAPPEASABLE
AUTHORITARIAN
UNCOMPROMISING
UNACCOMMODATING