I'm not posting anymore long code here unless someone asks me to.
I'll just add the attachment at the bottom. To use the attachment, just extract the dictionary.mrc file to your mirc directory and type /load -rs dictionary.mrc . If you don't know where your mirc directory is , type //echo -a $mircdir .
The syntax for this is !dict word or /dict word . This script is a little slow to respond, so be patient. You can turn the trigger off from the channel menu. There is also a reset switch there, incase the script gets stuck. Enjoy