Instructor has drink with singer (7)
I believe the answer is:
teacher
'instructor' is the definition.
(I know that instructor can be written as teacher)
'drink with singer' is the wordplay.
'drink' becomes 'tea' (tea is a drink).
'with' means one lot of letters go next to another.
'singer' becomes 'cher' (Cher is a US musician).
'tea'+'cher'='TEACHER'
'has' is the link.
(Other definitions for teacher that I've seen before include "School educator" , "One who educates" , "Hectare (anag)" , "'Instructor, educator (7)'" , "Guide" .)