What does "see" in "the Holy See" mean? The seat of the Bishop of Rome is called "the Holy See". What does "see" mean?

Does it mean “Holy Sea”, as the word “see” could be an archaic spelling of the word “sea”. It would make sense, because there is an unholy sea in the Bible also, called “Lake of fire”. It sure sounds like “Holy Sea”, because it makes most sense language-wise.
"See" comes from the Latin word sedes, which means "seat" or "chair".

"Holy See" is Sedes Apostolica (lit. "Apostolic Chair") in Latin.

The Oxford English Dictionary (OED) gives this etymology for see, n.1:


  Etymology: &lt; Anglo-Norman see, sed, sied, siet, sez, siez, Anglo-Norman and Old French se, sie, Middle French sie, siet dwelling (c 1100), capital city (c 1100), cathedral city (1139 or earlier), cathedral (a 1175), diocese (12th cent.), throne (second half of the 12th cent.), seat (second half of the 13th cent. or earlier), the papacy (1360) &lt; classical Latin sēdēs  seat (see sedes n.).
  
  Compare siege n.  and seat n.
  
  Compare Old Occitan ses, se, sea (12th cent.), Catalan seu (14th cent.), Spanish †sey, †sé, †seo (1266), Portuguese sé (13th cent.).


Also:


  [In patristic writers (e.g. Augustine, 5th cent.) post-classical Latin Sedes Apostolica ‘Apostolic See’ was applied more widely to any of the bishoprics founded by apostles; in medieval writers (e.g. in the 11th cent.) it occurs also in the general sense of ‘cathedral’.]


St. John Lateran's basilica is the Pope's cathedral (cathedra = chair), and this is his chair there: