Hide from everyone at first in state of agitation (7)
I believe the answer is:
leather
'hide' is the definition.
(an animal hide)
'everyone at first in state of agitation' is the wordplay.
'at first' suggests taking the first letters.
'in' is an insertion indicator.
'state of agitation' becomes 'lather' (as in the phrase 'in a lather').
The initial letter of 'everyone' is 'e'.
'e' inserted into 'lather' is 'LEATHER'.
'from' is the link.
(Other definitions for leather that I've seen before include "Material made from animal skin" , "Cured animal hide" , "Dressed hide" , "polish" , "Tanned animal skin" .)