give an order, sprout forth
吩 centers on issuing a command or causing something to emerge: giving an order or making something sprout forth. Both senses share the idea of a directed outward action.
吩 combines 口 (mouth) with 分, which likely contributes the sound and the idea of dividing or distributing, suggesting giving orders or causing something to issue forth.
A mouth 口 dividing 分 tasks: imagine a commander's mouth issuing orders that split responsibilities among soldiers, or a seed's mouth-like split from which a sprout emerges.
For フン, picture a fun commander giving orders with a grin: fun -> フン, and the mouth 口 is having fun dividing 分 tasks.