Suffix -ity. Used to form a noun from an adjective; especially, to form the noun referring to the state, property, or quality of conforming to the adjective's description. Used to form other nouns, especially abstract nouns. Usage notes . Many nouns formed with -ity are uncountable; those that are countable form their plurals in -ities.
Duncan Hazlett McGuire was an Australian musician, songwriter, recording engineer and producer. He was associated with vocalist, Doug Parkinson, in various groups during the 1960s and 1970s; McGuire was also a founding member of the jazz fusion band, Ayers Rock from 1973 until he left in 1976.
Duncan Keith. Duncan Keith (born July 16, 1983) is a Canadian professional ice hockey defenceman and an alternate captain for the Chicago Blackhawks of the National Hockey League (NHL). Keith is known as a two-way defenceman, capable in both shutdown and offensive roles. He is a three-time Stanley Cup champion with the Blackhawks in 2010, 2013 and 2015.