I am finding what I understand of this interesting, and I do enjoy a bit of linguistics, but perhaps I shouldn't have encouraged it a few pages ago. Carry on though.
(Raak) With "embolden" and "enliven" it would seem that in the past someone has done just that. I don't think the rules are particularly well-defined. (nights) Yep, we're a bunch of swivel-eyed fundamentalists. In the beginning was the Word. AND THE WORD SHALL BE SPELT PROPERLY. :-)
Is there an opposite for "enlarge" which has the same pattern? There doesn't seem to be an "ensmall" or "enlittle" (although there is "belittle" but then where's the "belarge"?) - the closest in meaning is probably "shrink," which seems to have no connection with any words meaning "small" whatsoever.
Darren] Well, there's the Simpsons' 'debigulator' machine, which rather implies that there's a verb 'to debigulate'
More seriously, since the 'en-' prefix mostly seems to mean 'more of', or 'increase' you wouldn't really expect a word for making smaller to be made up in that way. There is 'decrease', which is a Latinate construction of 'de-' and crescere, to grow.