Homographs, not to be confused with homonyms, are words which happen to be spelled identically but which have totally different meanings and etymologies. In addition to spelling, most homographic words share the same pronunciation. And so great is the spread of meanings - through association, figurative uses, and other influences - that many other words in English could be labeled pseudo-homographs: words with such widely disparate meanings that one would suppose them to come from entirely different sources, as the authentic homographs do.
Drury, Donald A.
"Homographs and Pseudo-Homographs,"
Word Ways: Vol. 2
, Article 10.
Available at: http://digitalcommons.butler.edu/wordways/vol2/iss3/10