Dour

austère

(stern, harsh and forbidding)

dur

(stern, harsh and forbidding)

entêté

(unyielding and obstinate)

inflexible

(unyielding and obstinate)

lugubre

(expressing gloom or melancholy)

morose

(expressing gloom or melancholy)

mélancolique

(expressing gloom or melancholy)

obstiné

(unyielding and obstinate)

rigide

(unyielding and obstinate)

rigoriste

(stern, harsh and forbidding)

rigoureux

(stern, harsh and forbidding)

sévère

(stern, harsh and forbidding)

taciturne

(expressing gloom or melancholy)

têtu

(unyielding and obstinate)