What does the idiom "Make a killing" mean?

• Make a killing

English Meaning: to earn a lot of money in a short time and with little effort / have great financial success.
Bangla Meaning: অর্থোপার্জনে অসাধারণ সাফল্য লাভ করা।

Hence, the idiom "Make a killing" means - To earn a lot of money quickly.

Ex. Sentence: They made a killing with the sale of their London house.
Bangla Meaning: তারা তাদের লন্ডনের বাড়িটা বিক্রি করে অনেক লাভবান হয়েছে।

Source: Lecture.