Where does “spleen” come from?

spleen (Polish) comes from English spleen, from Middle English splene, from Old French esplein, from Latin splēn, from Ancient Greek σπλήν, from Ancient Greek σπληχ-.

Ancestry of “spleen”, step by step

Step	Language	Word	Meaning
1	English	spleen	In vertebrates, including humans, a ductless...
2	Middle English	splene	—
3	Old French	esplein	—
4	Latin	splēn	spleen, milt
5	Ancient Greek	σπλήν	milt, spleen
6	Ancient Greek	σπληχ-	—

Every word from Ancient Greek σπληχ- →Every word from Ancient Greek σπλήν →Every word from Latin splēn →