I'd have to agree with SuicideJunkie on the KISS principle. 9MB is nothing these days, and really wall you want it simple word lookups. I can identify because, though I'm a native English speaker, when I tried to read Patrick O'Brien's Master and Commander books (which are truly awesome, btw), I ended up bringing up my giant unabridged Webster's dictionary every page or so. Sometimes it wasn't words I didn't know, but words I knew that I suspected he was making archaic use of. That ended up being a Killer App for me to buy a Palm Pilot, as that was the only platform any unabridged English dictionary was available for (Webster's, again). That way, instead of physically manhandling this paper monstrousity, I could just keep my Palm Pilot nearby and just look up words. So I say screw it, keep it simple in memory, and utilize Term::Readkey or some such to monitor keystrokes and start showing suggestions, a la Youtube's search box javascript.