strengthen

verb

Etymology: From rare Middle English strengthenen (14th c.), from earlier strengthen (12th c.), where -en is the infinitive ending. Probably the original form was reinterpreted as strength + -en around the time when the infinitive ending was being apocopated in late Middle English.

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

   “strengthen a muscle”

   “strengthen a wall”

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

   “Charge Joshua, and encourage him, and strengthen him.”

   “my father and mother strengthened me in this my first impression, saying in my presence, I was intended for some great purpose”

3. To augment; to improve; to intensify.
4. To reinforce, to add to, to support (someone or something)

   “strengthen an army”

   “Each half-section of the battery weighs about eight tons, and the two underframes had to be strengthened to take this weight.”

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

   “strengthen the cause”

6. To grow strong or stronger.

   “my affection seems so superfluous that I often wonder why it should be so strong. But wise or foolish, there it is, strengthening with the years whether I will or no”