font (n.1) Look up font at
"water basin," especially used in baptism, late Old English, from Latin fons (genitive fontis) "fountain" (see fountain), especially in Medieval Latin fons baptismalis "baptismal font." The word is sometimes used poetically for "a fountain; a source."
font (n.2) Look up font at
"complete set of characters of a particular face and size of type," 1680s (also fount), earlier "a casting" (1570s), from Middle French fonte "a casting," noun use of fem. past participle of fondre "to melt" (see found (v.2)). So called because all the letters in a given set were cast at the same time.