closely contested constituency; highly competitive marketplace; battleground
Used for electoral districts with fierce competition, markets with many rivals, or any area of intense rivalry. The figurative sense 'battleground' is common.
This electoral district becomes a closely contested constituency between the ruling and opposition parties every time.
New ramen shops are opening one after another in front of the station, making it a highly competitive marketplace.
Compound of 激戦 (fierce battle) + 区 (ward, district). The exact historical derivation is uncertain, but the word is conventionally used for areas of intense competition.