hòu​yuán

backup

后援 (後援) hòu​yuán
backup noun
support or backing provided by a person, group, or organization

Fans formed a fan club to support the singer.

reinforcement noun
additional personnel or resources sent to strengthen a military or operational force

Frontline troops are in urgent need of reinforcements.

Frequency

Movie subtitles
6.86 per million appears in 3% of films
Written text
1.72 per million

Sources

Definitions
CC-CEDICT