Nouns:
* Business: The state of being busy or active.
* Busyness: The state of being busy; excessive or hurried activity.
Adjectives:
* Busy (base form)
* Busier (comparative)
* Busiest (superlative)
Verbs:
* Busying (present participle)
* Busied (past participle)
* Busies (third person singular present)
Adverbs:
* Busily: In a busy manner.
Let me know if you would like to explore any of these word forms in more detail!