Relative nearly left establishment that struggles to maintain social distancing (7)
I believe the answer is:
brothel
'establishment that struggles to maintain social distancing' is the definition.
(place where people are physically close together)
'relative nearly left' is the wordplay.
'relative' becomes 'brother' (brother is a kind of relative).
'nearly' means to remove the last letter.
'left' becomes 'L' (common abbreviation).
'brother' with its final letter removed is 'brothe'.
'brothe'+'l'='BROTHEL'
(Other definitions for brothel that I've seen before include "It's given here!" , "House of ill repute" , "Stews" , "House of prostitution" , "oldest professional establishment?" .)