Latin 'cuppa' became English 'cup' and German 'Kopf' (head) — Roman soldiers called skulls 'cups.'
A small, open container used for drinking, typically with a handle; also a unit of volume in cooking.
From Old English 'cuppe,' an early borrowing from Late Latin 'cuppa' (cup, drinking vessel), a variant of Latin 'cūpa' (tub, cask, vat). The Latin word may ultimately derive from a pre-Indo-European Mediterranean substrate language, as similar words appear in Greek 'kypellon' (goblet) without clear PIE etymology. The word entered Germanic very early, likely through Roman trade contacts
German 'Kopf' (head) descends from the same Latin 'cuppa' that gave English 'cup.' The semantic shift from 'drinking vessel' to 'head' occurred through soldiers' slang — Roman legionaries called a skull a 'cuppa' (cup), and the metaphor stuck in Germanic, eventually becoming the standard German word for 'head.'