Answer: ahum

AnswerCrossword Clue
AHUMBuzzing
AHUMSuper-busy
AHUMBuzzing with activity
AHUMBusy, in a way
AHUMExtremely busy
AHUMWhirring.
AHUMBee-loud.
AHUMBuzzing.
AHUMBustling with activity.
AHUMLike a beehive.
AHUMBusy.
AHUMNoisily busy
AHUMAudibly active
AHUMLike a beehive