English Signal Officer initially concealing urge for drink (8)
I believe the answer is:
espresso
'for drink' is the definition.
(espresso is a kind of drink)
'english signal officer initially concealing urge' is the wordplay.
'english' becomes 'e' (abbreviation).
'initially' suggests taking the first letters.
'concealing' indicates putting letters inside.
'urge' becomes 'press' (synonyms).
The initial letters of 'signal officer' is 'so'.
'so' going around 'press' is 'spresso'.
'e'+'spresso'='ESPRESSO'
(Other definitions for espresso that I've seen before include "Italian-style coffee" , "Coffee (S, not X)" , "Coffee-making machine" , "strong drink" , "Drinks machine" .)