1. To involve a lot of effort or energy and to be not easy to do, understand, or solve. English = (be) difficult, (be) hard.
2. To be tiring and involving a lot of effort. English = (be) arduous, (be) strenuous.
3. Of a person (especially one in authority), to not tolerate impolite or disobedient behaviour and to insist that others follow the rules without exception. English = (be) strict, (be) hard, (be) harsh.