(s)severe, spartanunsparing and uncompromising in discipline or judgment“a parent severe to the pitch of hostility” (H.G.Wells), “a hefty six-footer with a rather severe mien”, “a strict disciplinarian”, “a Spartan upbringing”
(s)ascetic, ascetical, austere, spartanpracticing great self-denial“Be systematically ascetic...do...something for no other reason than that you would rather not do it” (William James), “a desert nomad's austere life”, “a spartan diet”, “a spartan existence”