Gift that is beneath host (7)
I believe the answer is:
pressie
'gift' is the definition.
(short for 'present')
'that is beneath host' is the wordplay.
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'beneath' says to put letters next to each other (in a down clue).
'host' becomes 'press' (both can mean a crowd of people).
'ie' after 'press' is 'PRESSIE'.
(Other definitions for pressie that I've seen before include "Gift (colloq.)" , "Informally, offering" , "Something freely given" .)