What does HARD mean?

adjective

1. not easy; requiring great physical or mental effort to accomplish or comprehend or endure“a difficult task”
2. dispassionate“took a hard look”
3. resisting weight or pressure
4. very strong or vigorous“strong winds”
5. characterized by effort to the point of exhaustion; especially physical effort“worked their arduous way up the mining valley”
6. produced without vibration of the vocal cords“unvoiced consonants such as `p' and `k' and `s'”
7. (of light) transmitted directly from a pointed light source
8. (of speech sounds); produced with the back of the tongue raised toward or touching the velum“Russian distinguished between hard consonants and palatalized or soft consonants”