I've been pointed in the direction of the wonderful visuwords application by Eva. describing itself as an 'online graphical dictionary', it assembles words in space depending on their relationship to each other. so in the above example brandmark (verb: "mark with a brand or trademark") is three steps away from symbol (noun: "an arbitrary sign (written or printed) that has acquired a conventional significance).
it would be even cooler if you could click on a word and then
subsequently see the association cloud emerge from that word; but then
you wouldn't want to lose too many hours on a word association
breadcrumb trail…
a great tool for quick desk reference when writing decks, brainstorms or to explore the word associations of brand names or positionings. try typing in Absolute for example, and you're not far away from arbitrary, living and infinite; not such bad word-company for a radio brand in the early 21st Century.
MEDIATION 
Hey Chris, good find. I’d seen the similar Visual Thesaurus site (http://www.visualthesaurus.com)a little while ago, but that’s a bit crap cos you have to pay to have more than one go at it. Had a play and it turns out you CAN double click on at least some of the words that spring out and go on a “breadcrumb trail.” Hours of fun… and potentially an engaging way of taking clients through the meanings associated with brand essences etc. as you say.