Female downing two halves -- Courage? -- in party game (4,3,6)
I believe the answer is:
spin the bottle
'party game' is the definition.
(I've seen this before)
'female downing two halves courage?' is the wordplay.
'female' becomes 'she' ('she' refers to a woman).
'downing' indicates putting letters inside (to down food or drink is to swallow it quickly).
'two halves' becomes 'pint' (two half-pints).
'courage?' becomes 'bottle' (bottle can mean courage).
'she' placed around 'pint' is 'spinthe'.
'spinthe'+'bottle'='SPIN-THE-BOTTLE'
'in' is the link.
(Other definitions for spin the bottle that I've seen before include "drinking game" , "daring game" , "party game" .)