reinforce

verb

re·​in·​force ˌrē-ən-ˈfȯrs 

variants or less commonly reenforce

reinforced also reenforced; reinforcing also reenforcing; reinforces also reenforces

transitive verb

1

: to strengthen by additional assistance, material, or support : make stronger or more pronounced

reinforce levees

reinforce the elbows of a jacket

reinforce ideas

2

: to strengthen or increase by fresh additions

reinforce our troops

were reinforcing their pitching staff

3

: to stimulate (a subject, such as an experimental animal) by reinforcement (see reinforcement sense 3)

also : to encourage (a response) by reinforcement

intransitive verb

: to seek or get reinforcements

reinforceable

ˌrē-ən-ˈfȯr-sə-bəl 

adjective

Synonyms of reinforce

• bolster
• prove
• support

Examples of reinforce in a Sentence

The captain sent out another squad to reinforce the troops.

Our camp is reinforced with supplies flown in by helicopter.

The levees will need to be reinforced.

The bad weather forecast only reinforces our decision to leave early tomorrow.

Some critics say that the movie reinforces negative stereotypes about the military.

We do our best to reinforce good conduct in the classroom.

Recent Examples on the Web

These tubes can also reinforce polymers or metals while maintaining conductivity. —Aamir Khollam, Interesting Engineering, 30 Jan. 2026

As Morrison pointed out, representations and practices can be mutually reinforcing. —Literary Hub, 30 Jan. 2026

Saudi Arabia's ambition to achieve net-zero emissions by 2060 reinforces the need to align growth, sustainability, and national priorities in a way that is grounded in operational reality. —CBS News, 29 Jan. 2026

Together, this dual footprint reinforces Gantri Made’s foundation as a digital manufacturing platform with global reach. —Sofia Celeste, Footwear News, 29 Jan. 2026

Word History

Etymology

re- + inforce, alteration of enforce

First Known Use

15th century, in the meaning defined at transitive sense 1

Rhymes for reinforce

• counterforce
• intercourse
• nonrecourse
• watercourse
• bourse
• coarse
• course
• force
• gorse
• hoarse
• horse
• norse

Kids Definition

reinforce

verb

re·​in·​force ˌrē-ən-ˈfō(ə)rs 

-ˈfȯ(ə)rs

1

: to strengthen by additional assistance, material, or support

reinforce the elbows of a jacket

reinforce the argument with facts

2

: to strengthen or increase by fresh additions

were reinforcing their pitching staff

reinforce our troops

3

: to stimulate (a person or animal) with a reinforcer

also : to increase the frequency of (a response) with a reinforcer

Medical Definition

reinforce

transitive verb

re·​in·​force ˌrē-ən-ˈfō(ə)rs, -ˈfȯ(ə)rs 

reinforced; reinforcing

1

: to strengthen by additional material or support : make stronger

reinforced with vitamins

2

: to stimulate (as an experimental animal or a student) by reinforcement

also : to encourage (a response) by reinforcement

reinforceable

-ə-bəl 

adjective