Nyms and Onyms

Words in English with the suffix -onym or -nym (from the Greek onoma - "name") refer to words with a particular property. For example an acronym is a word formed from the initial letters of other words.

For more detail and further examples see http://en.wikipedia.org/wiki/-onym

acronym: a word formed from the initials of one or more words that is pronounceable like a normal word, such as NATO [pronounced nay-toe, not as N-A-T-O. This is not the same as an abbreviation or initialism
antonym: a word with the exact opposite meaning of another word; hot & cold, soft & hard
aptronym: a name appropriate to its owner's occupation or physical properties, such as "Goldsmith" or "Longman"
charactonym: a name of a fictional character reflected in his personality traits, such as Shakespeare's Pistol or Bottom
contronym or antagonym: a word that may have opposite meanings in different contexts, such as cleave meaning "stick together" or "split apart"
eponym: a botanical, zoological, artwork, or place name that derives from a real or legendary person; such as einsteinium for Albert Einstein, and many foods
heteronym: a word that is spelled in the same way as another but that has a different sound and meaning, for example "bow" as in "bow of a ship" or "bow and arrow" (compare "homonyn")
homonym: a word that is pronounced and spelled the same way as another, but has a different meaning, such as bat as in "fruit bat" or "bat and ball" (compare "heteronym", "isonym")
synonym: a word equivalent in meaning or nearly so to another word; a word that may be substituted for another word that has the same or a similar meaning, such as near and close (compare "antonym")