A rainy day( দুর্দিন ) Everybody should save something for rainy day.
Nip in the bud( অঙ্কুরে বিনষ্ট করা ) All his hopes were nipped in the bud.
A bolt from the blue( সম্পূর্ন অপ্রত্যাশিত ) The news of his father's death came to him as a bolt from the blue.
By and by( শীঘ্র ) He will come here by and by.
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.
