Harden

1. v. i. To become confirmed or strengthened, in either a good or a bad sense.
2. v. t. To make hard or harder; to make firm or compact; to indurate; as, to harden clay or iron.
3. v. t. To accustom by labor or suffering to endure with constancy; to strengthen; to stiffen; to inure; also, to confirm in wickedness or shame; to make unimpressionable.
4. v. i. To become hard or harder; to acquire solidity, or more compactness; as, mortar hardens by drying.

The word meanings were obtained from OPTED(The Online Plain Text English Dictionary), which is based on “The Project Gutenberg Etext of Webster’s Unabridged Dictionary” which is in turn based on the 1913 US Webster’s Unabridged Dictionary (See Project Gutenburg), as a text file.