Wordpress: How can I group posts without using categories or tags? -

i'm creating dynamic dictionary wordpress la http://urbandictionary.com/. functionality want emulate having multiple definitions single word. need each of these definitions able rated user (currently using wp-postratings, i'm open other plugin). idea users determine accurate definition of word via post ratings system.

currently have each definition individual post same title, e.g., definition #1 "dog" , definition #2 "dog" separate posts title "dog." here's i'm running trouble: don't want user aware of structural distinction between different definitions. in other words, don't want there 2 separate pages—i want user think, intents , purposes, there singular page contains of word's definitions.

this similar categories do, obviously, i'm categorizing words content. i'm looking more explicit connection between posts. (i prefer not have 500+ categories.)

would easier input secondary definitions custom field values, rather separate posts? worry no plugin knowledge allows user rate other singular posts in entirety.

does have idea how can set up? i've searched days , haven't found applicable solution. appreciated. makes sense. difficult problem me articulate.

tl;dr: can create, using custom fields or plugin or whatever else, more explicit connection between posts categories or tags?

i ended going joe buckle's idea, making each definition comment. styled comments template match going for. bit of workaround gets job done. thanks.