Public house gets a single call (5)
I believe the answer is:
phone
'call' is the definition.
(phone can mean to call by telephone)
'public house gets a single' is the wordplay.
'public house' becomes 'ph' (abbreviation).
'gets' means one lot of letters go next to another.
'a single' becomes 'one' (a single thing - only one).
'ph'+'one'='PHONE'
(Other definitions for phone that I've seen before include "Mobile, perhaps" , "Covert monitoring of electronic exchanges" , "Short piece of electronic equipment" , "It converts sounds into signals and back again" , "Call, ring" .)