Mean attitude not endearing to host (6)
I believe the answer is:
denote
'mean' is the definition.
(I know that denote is a more specific form of the action mean)
'attitude not endearing to host' is the wordplay.
'to host' says the answer is hidden in the clue (I've seen 'hosts' mean this).
'DENOTE' is hidden in the letters of 'attitude not endearing'.
(Other definitions for denote that I've seen before include "Point" , "Indicate, be a sign of" , "Need to (anag) - indicate" , "Be an indication of" , "Be the sign or symbol of" .)