Answer: sternest

AnswerCrossword Clue
STERNESTMost unrelenting.
sternesturdy stout a stern resolve
sternestSTERN, unyielding
sternestexorable stern necessity
sternesthaving a definite hardness or severity of nature or manner austere
STERNESTMost unforgiving
STERNESTMost austere
STERNESTSuperlatively severe
STERNESTMost demanding
STERNESTMost forbidding
STERNESTMost unrelenting
STERNESTMost severe
STERNESTMost uncompromising.
STERNESTLeast lenient.
STERNESTMost rigorous.
STERNESTMost inexorable.
STERNESTHarshest.
STERNESTMost severe.
STERNESTMost strict
STERNESTLeast lenient
STERNESTMost unyielding
STERNESTLeast indulgent