What is the meaning of Strengthen?

To make strong or stronger; to add strength to; to increase the strength of; to fortify.

To empower; to give moral strength to; to encourage; to enhearten.

To augment; to improve; to intensify.

To reinforce, to add to, to support (someone or something)

To substantiate; to corroborate

To grow strong or stronger.

to strengthen, fortify (increase the strength of)

to empower, to augment (increase the potency or severity of)

to enhearten, to encourage (increase the morale of)

to assist, to support (someone or something)

to substantiate; to corroborate (a belief, argument, etc.)

to approve or validate (a document).

to endeavour; to rouse oneself.

Source: wiktionary.org