solid, firm, and resistant to pressure

requiring a lot of effort

कड़ी मेहनत

English Usage: He put in hard work to achieve his goals.

Hindi Usage: उसने अपने लक्ष्यों को पाने के लिए कड़ी मेहनत की।

difficult to do or deal with

ठोस

English Usage: The surface was too hard to drill.

Hindi Usage: सतह इतनी ठोस थी कि उसे ड्रिल नहीं किया जा सकता था।

an attribute of something that is firm or solid

कठोरता

English Usage: The hard of the rock made it difficult to carve.

Hindi Usage: चट्टान की कठोरता ने इसे तराशना कठिन बना दिया।

to make or become stronger or more difficult

कठिन करना

English Usage: He needs to harden his attitude towards criticism.

Hindi Usage: उसे आलोचना के प्रति अपनी भावना को कठोर करना होगा।