Hold good( প্রযুক্ত হওয়া ) This ruls will not hold good here.
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.
All at once( হঠাৎ ) All at once a tiger came out of the forest.
At stake( বিপন্ন ) His life is at stake now.
In the mean time( ইতিমধ্যে ) Lila will come here to-night. In the mean time you should get her room ready.