English Reference
noun

reinforcement

n.
US /ˌɹiɪnˈfɔɹsmənt/ UK /ɹˌiːɪnfˈɔːsmənt/ re·in·force·ment UK spelling reinforcement's, reinforcement's

  1. 01 B2 Upper Intermediate

    the act of making a structure or material stronger by adding something to it.

    the physical strengthening of an object or material through the addition of supportive elements.

    Simple

    The old bridge needed steel reinforcement to handle the weight of modern trucks.

    In context

    Engineers recommended carbon-fiber reinforcement for the concrete pillars to ensure the building could withstand seismic activity.

  2. 02 B2 Upper Intermediate

    extra soldiers, planes, or ships sent to help an army during a battle.

    additional personnel or equipment sent to augment a military force during an operation.

    Simple

    The captain called for reinforcements when he realized they were outnumbered.

    In context

    The arrival of aerial reinforcements turned the tide of the battle, providing the ground troops with much-needed cover.

  3. 03 B2 Upper Intermediate Academic Psychology

    a reward or consequence that makes a person or animal want to repeat an action.

    the process of encouraging or establishing a pattern of behavior by offering a reward or removing a negative stimulus.

    Simple

    Giving the dog a treat for sitting is a form of positive reinforcement.

    In context

    The study examined how intermittent reinforcement schedules can make a specific behavior more resistant to extinction over time.

In Cali, the country’s third largest city,  authorities reported multiple landslides with people trapped and requested reinforcements for rescue operations .

UN News· 11 Aug 2026

In Cali, the country’s third largest city, authorities have reported multiple landslides with people trapped and have requested reinforcements for rescue operations .

UN News· 10 Aug 2026

From reinforce + -ment.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated