| bullheaded(adjective, tough, firm, determined, resolute) |
| constant(adjective, clear, firm, fixed, resolute) |
| critical(adjective, severe) |
| demanding(adjective, severe) |
| emphatic(adjective, definite, unqualified) |
| exacting(adjective, severe, severity) |
| extreme(adjective, convention) |
| forbidding(adjective, harsh) |
| immutable(adjective, hard, secure, rough, firm) |
| indomitable(adjective, hard, tough, difficult, resolute) |
| intolerant(adjective, severe) |
| irreconcilable(adjective, hostile, conflicting) |
| merciless(adjective, hard, rough, harsh, cruel) |
| opinionated(adjective, determined, resolute, strongly, unshakeable) |
| oppressive(adjective, severe, severity) |
| orthodox(adjective, conformity) |
| perverse(adjective, mean, hard, firm, deliberate) |
| positive(adjective, clear, certain, definite, severity) |
| recalcitrant(adjective, tough, firm, difficult, violent) |
| self-willed(adjective, tough, firm, difficult, determined) |