Hey, so I've been building a vocab.000 file from scratch and I think it is possible to have 'multiple part' words. I discovered this with mokalus's utility which I found on the agigames site for converting a words.tok file (agi) to a vocab.000 (sci). I ran it against an agi game and imported the resulting file into SCI Comp, and sure enough, I have words like 'bolt of lightning'.
I'm still in the process of building a vocab.000 file from scratch, and I'm thinking of perhaps making a utility which allows you to construct an entire vocab file from a spreadsheet. Alternately, you could always create a 'multi part' word in the vocab file with all the spaces replaced with an arbitrary printable character, then export the resource & edit it with a hex editor, replacing your bogus character references with a 0x20 (space character) and then re-import the file into your game.
The one thing that I'm not clear on is if the parser can handle these words. Part of me thinks that it probably chops a sentence up using the spaces, but maybe not necessarily?