Flat has garden — we hear sound of bees (2-3)
I believe the answer is:
ho-hum
'flat' is the definition.
(thesaurus)
'garden we hear sound of bees' is the wordplay.
'garden' becomes 'hoe' (to garden could mean to hoe).
'we hear' shows a homophone (sound like).
'sound of bees' becomes 'hum' (a humming or buzzing sound).
'hoe' sounds like 'ho'.
'ho'+'hum'='HO-HUM'
'has' is the link.
(Other definitions for ho-hum that I've seen before include "Ah well!" , "Interjection" , "Exclamation to express resignation or boredom" , "Expression of a yawn or indication of boredom" , "Routine" .)