The phrase 'At large' means -

♦ At large
English Meaning: at liberty / free
Bangla Meaning: স্বাধীন। 

Ex. Sentence: Corrupted govt. officials are still at large.
Bangla Meaning: দুর্নীতিবাজ সরকারি কর্মকর্তারা এখনো মুক্ত অবস্থায় আছে।

Options,
- At last
English Meaning: in the end; after much delay.
Bangla Meaning: অবশেষে। 

- At once
English Meaning: immediately.
Bangla Meaning: দেরি না-করে / এক্ষুনি। 

Source: Website Lecture.