Half-mute Parisian who starts to lose adventurous spirit (7)
I believe the answer is:
tequila
'spirit' is the definition.
(alcoholic spirit)
'half-mute parisian who starts to lose adventurous' is the wordplay.
'half' suggests halving the letters.
'parisian who' becomes 'qui' ('who' in French).
'starts to' says to take the initial letters.
The first letters of 'lose adventurous' is 'la'.
'mute' with half the letters taken is 'te'.
'te'+'qui'+'la'='TEQUILA'
(Other definitions for tequila that I've seen before include "Quit ale for Mexican spirit" , "Distilled agave drink" , "Cocktail -- 1988 American crime film -- equaliser units (anag)" , "Liquor made from the agave plant" , "Mexican agave spirit" .)