Fetching details from the dictionary...
hard fight; close game; struggle; tight contest
彼は初戦で苦戦した。
He struggled in the first match.
新興企業は市場で苦戦を強いられた。
The startup was forced to struggle in the market.
候補者は苦戦の末、辛くも当選した。
The candidate barely won the election after a hard struggle.