Inki...as much as I love the reasoning and all, technicallky, STIL is an ancronym and not a word, but you get extra bonus points for effort....
New game, new word:
Radar and sonar are acronyms and are excepted words.
a word formed from the initial letters or groups of letters of words in a set phrase or series of words, as Wac from Women's Army Corps, OPEC from Organization of Petroleum Exporting Countries, or loran from long-range navigation.
English major. Word games are my favorites.