A heavy or crushing defeat (losing by a large margin).
昨日の試合は相手に大負けしてしまった。
We were badly beaten in yesterday's game.
選挙であの党は大負けを喫した。
That party suffered a crushing defeat in the election.
ギャンブルで大負けして、今日は何も買えない。
I lost big gambling and can't buy anything today.
A big discount; selling at a large markdown (heavy reduction in price).
在庫処分で店は大負けして商品を放出した。
To clear inventory the shop sold items at deep discounts.
決算の都合で今年は大負けセールを行うそうだ。
Due to accounting reasons, they're having a big clearance sale this year.