| Term | Definition |
| homogeneous | uniform in structure or composition |
| hubris | overbearing pride |
| hypotenuse | the side of a right triangle opposite the right angle |
| impeach | to charge a public official with improper conduct |
| incognito | disguised or concealed identity |
| incontrovertible | impossible to dispute |
| inculcate | to impress something upon the mind of another by frequent instruction |
| infrastructure | the basic facilities needed for a functioning society |
| interpolate | to insert between; also, to alter or corrupt by insertion. |
| irony | the use of words to express the opposite of their literal meaning |