The extension of a file 'pdf' stands for:

Miscellaneous

A paper written by hand-Manuscript

Not bearing the name of a writer- Anonymous

Animals living in flocks-Gregarious 

Animals living in both water and land-Amphibians

Animals sucking their mothers' breast-Mammals

Beyond the power of nature Supernatural (অতিপ্রাকৃতিক)

Fit to be eaten-Edible

A speech delivered without previous preparation- Extempore speech (উপস্থিত বক্তৃতা)

A remedy for all diseases-a panacea 

A speech full of too many words - A verbose speech 

A speech delivered for the first time in the assembly- A maiden speech (উদ্বোধনী বক্তৃতা)