What is the meaning of Ad lib in bengali?

Meaning(s):

1. without advance preparation
2. बिना तैयारी का = extemporaneous an ad lib performance
3. यथेच्छ = how He spoke ad lib.
4. बिना तैयारी के = how He is famous for singing ad lib.
5. इच्छानुसार = how He spoke ad lib.
6. तत्काल भाषण देना = perform She often forgot her lines on stage but she was very good at ad libbing.
7. बिना तैयारी के बोलना = perform She had no time to prepare but she beautifully ad libbed her lines.
8. बिना तैयारी के ही सुनाना = perform They ad libbed the duet.
9. बिना तैयारी के देना = perform He ad libbed a speech at the wedding.
10. Ad libitum, Spontaneously, Impromptu