adjective

having a great deal to do.

he had been too busy to enjoy himself

occupied (in),engaged in,involved in,employed in,working at,labouring at,toiling at,slaving at,hard at work (on),wrapped up (in/with),rushed off one’s feet (with),hard-pressed,time-poor,at work (on),on the job,absorbed in,engrossed in,immersed in,preoccupied with,active (in),lively,industrious,bustling,energetic,tireless,busy as a bee,on the go,hard at it,on the hop,have one’s hands full