Definitions

1. adjective

difficult to do or achieve, needing great effort or skill

“The teacher said the math problem was hard to solve.”

2. noun

a hard object or surface

“She hit her head on the hard floor.”

3. adverb

in a firm or unyielding manner

“He worked hard on the project.”

4. verb

to make something harder or more difficult

“The cold weather will hard the ground.”