Stiff

inflexibel

(figuratively: of policies and rules and their application and enforcement)

rigide

(of an object, rigid, hard to bend, inflexible)

stevig

(colloquial: harsh, severe)

stijf

(of an object, rigid, hard to bend, inflexible)

stijf

(of muscles, or parts of the body)

stug

(of an object, rigid, hard to bend, inflexible)

stug

(of a person, formal in behavior, unrelaxed)