Definitions from Wiktionary ( )

▸ verb:  (transitive) To make strong or stronger; to add strength to; to increase the strength of; to fortify.
▸ verb:  (transitive) To empower; to give moral strength to; to encourage; to enhearten.
▸ verb:  (transitive) To augment; to improve; to intensify.
▸ verb:  (transitive) To reinforce, to add to, to support (someone or something)
▸ verb:  (transitive) To substantiate; to corroborate (a belief, argument, etc.)
▸ verb:  (intransitive) To grow strong or stronger.

---

▸ Words similar to strengthen
▸ Usage examples for strengthen

▸ Idioms related to strengthen
▸ Wikipedia articles (New!)
▸ Words that often appear near strengthen
▸ Rhymes of strengthen

▸ Invented words related to strengthen