a.
1.
Rigid, stern, strict, sharp, harsh, bitter, austere, rigorous, stiff, strait-laced, hard, unrelenting, relentless, inexorable, peremptory, censorious, cruel, bitter, morose.
2.
Strict, exact, accurate, methodical.
3.
Simple, plain, unadorned, chaste.
4.
Caustic, satirical, sarcastic, keen, cutting, stinging, biting, sharp, harsh, bitter, cruel, trenchant.
5.
Distressing, afflictive, acute, violent, extreme, intense, sharp.
6.
Serious, earnest, sedate, grave, austere, sober.
7.
Exact, critical, rigorous, hard.