At bay ( কোনঠাসা ) The tiger was at bay in the bush.
A rainy day ( দুর্দিন ) Everybody should save something for rainy day.
Pros and cons ( খুঁটিনাটি ) You should consider the Pros and cons of the system.
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.
Hold good ( প্রযুক্ত হওয়া ) This ruls will not hold good here.
Bring to book ( শাস্তি দেওয়া ) He should be brought to book for his misconduct.