Who first used the word "homomorphism" to describe a link between two similar structures ? Following this, who specialized this concept with the words: - "Isomorphism"; - "Endomorphism"; - "Automorphism" ? Gérard Lang
According to Jeff Miller's Earliest known uses of Some of the Words of Mathematics,
HOMOMORPHISM is found in English in 1935 in the Duke Mathematical Journal [OED].
A Google search for dates gives the same result.
UPDATE Thanks for your comments. After a more extended dates search, it appears that the word was in use in the mid 18th century, then disappeared from screens for more than 50 years!
This kind of search seems to output results dating back to 1869, but I stand a bit suspicious regarding what you get by clicking on them.