I'm Not An Idiot (but I play one on TV)
Duh. Thanks to Dolmere for sending me a dictionary link, which actually made a neuron fire (Shocking, I know! And at work too!) and reminded me that I have a FireFox plugin/extension/add-on/thing-what-makes-stuff-go that does the same sort of thing. DictionarySearch. Looks up a word and opens it in a separate tab. I've had it installed both at work and at home for ages. Upgraded regularly. Dumb dumb dumb not to think of it. I blame cancer. What? Fuck off, I'm allowed to.