Question

give one word meaning for that which surrounds our earth in all directions

Answer 1

its atmosphere 
i think soo

Answer 2

Answer:

One word substitution tests our ability to express the meaning of a phrase or a clause in a single word. These tests are helpful in determining the vocabulary and communication skills of an individual.

Cambridge English Dictionary defines 'atmosphere' as 'the mixture of gases that surrounds some planets, such as the earth; the air.'

So, one word substitution of 'that which surrounds our earth in all directions' is atmosphere.