C2 adjective /ʌnˈflæpəbəl/
unflappable
অচঞ্চল
Meaning
calm and composed, especially in difficult situations
Example
Despite the crisis, he remained unflappable and confident.
সংকট সত্ত্বেও সে অচঞ্চল ও আত্মবিশ্বাসী ছিল।