The Collaborative International Dictionary
Portgrave
Portgreve \Port"greve`\, Portgrave \Port"grave`\, [AS.
portger[=e]fa; port a harbor + ger[=e]fa a reeve or sheriff.
See Reeve a steward, and cf. Portreeve.]
In old English law, the chief magistrate of a port or
maritime town.; a portreeve. [Obs.]
--Fabyan.
Wiktionary
portgrave
n. (alternative form of portgreve English)