A rainy day( দুর্দিন ) Everybody should save something for rainy day.
Lion's share( সিংহভাগ ) He took the lion's share of the profit.
A blessing in disguise( বিপরীতে হিত ; প্রথমে খারাপ হিসেবে মনে হলেও পরবর্তীতে ভালো হয় ) Sam's motorcycle accident was a blessing in disguise because he got enough insurance money.
Steer clear of( এড়াইয়া চলা ) You must steer clear of evil company.
By and large( প্রধানতঃ ) People in our village are by and large farmers.
Turn over a new leaf( নূতনের সূচনা ) After his failure he turned over a new leaf.