Definitions from Wiktionary ( )

▸ verb:  (intransitive) To become hard.
▸ verb:  (transitive, ergative) To make something hard or harder.
▸ verb:  (transitive, figurative) To strengthen.
▸ verb:  (transitive, computing) To modify (a website or other system) to make it resistant to malicious attacks.
▸ verb:  (ambitransitive) To become or make (a person or thing) resistant or less sensitive.
▸ verb:  (intransitive, informal) To get an erection.
▸ verb:  (ambitransitive, phonology) To become or make (a consonant) more fortis; to (cause to) undergo fortition.
▸ verb:  (Slavic phonology) To unpalatalize or velarize.
▸ noun:  A surname.
▸ noun:  A place name:
▸ noun:  A suburb in the Metropolitan Borough of Walsall, West Midlands, England (OS grid ref SK0101).
▸ noun:  A village and civil parish (with a village council) in the Metropolitan Borough of Bradford, West Yorkshire, England (OS grid ref SE0838).
▸ noun:  A town in Hilltops council area, southern New South Wales, Australia.
▸ noun:  Alternative form of hurden (“coarse linen”) [(UK, dialect) A coarse kind of linen made from hurds.]

---

▸ Words similar to harden
▸ Usage examples for harden

▸ Idioms related to harden
▸ Wikipedia articles (New!)
▸ Popular adjectives describing harden
▸ Words that often appear near harden
▸ Rhymes of harden

▸ Invented words related to harden