So sometimes (especially during Te Wiki o te Reo Māori) I'm reading stuff on the web and come across a kupu hou I don't recognise and want to look up. I used to select this, open a new tab, type in http://www.maoridictionary.co.nz/, wait for it to load, and paste the word in.
Then I went on a javascript bookmarklet spree and among the simple bookmarklets I made (aka created in a Frankensteinian mashup of at least two other people's unrelated bookmarklets) was this one:
He aha?
Click and drag the link into your browser bookmarks bar. Then you can just select any word(s) and click the bookmarklet. It will pop up a new window which looks up the word for you; when you're done reading, close it and you're back to reading.