Sentence:  This annual March gathering of the digital elite, held at a resort near Tucson, is a combination of a three-day <WSD>free-form</WSD> think tank and schmooze-athon where the latest trends are dissected and, in the corridors or on the golf course, deals are hatched. 
Meaning of the word marked with <WSD> tags:  Having an unconventional, variable or asymmetric form.