large head, many, high, to divide, to distribute
肦 centers on the idea of a large head, which extends to notions of prominence (high) and abundance (many). The meanings "to divide" and "to distribute" seem to come from the right-side component 分 rather than the whole character's core idea, so they may be separate or derived senses.
肦 combines the flesh radical ⺼ with 分. The exact historical origin is uncertain; it may have originally depicted a large head or been a variant of another character. The modern form visually suggests a body part (⺼) related to division (分), but this is speculative.
The flesh radical ⺼ suggests a body part, and 分 means divide. Imagine a head so large it looks like it's been divided from the rest of the body—hence "large head." From there, think of a high, prominent head or many heads.
For フン, picture a large-headed figure named Fun who always divides snacks among friends: Fun -> フン, and his big head stands out.