Unusually adverb – To a remarkable degree or extent. Extra is a synonym for unusually in property topic. You can use "Extra" instead an adverb "Unusually", if it concerns topics such as extremely, uncommon. Nearby Word: unusual
Unreal Tournament 2004 included several bonuses in the collector's edition, which—unusually for CE versions—came at no extra charge to those that pre-ordered.
Vetinari only appears slightly tipsy, but then he stubs his toe on a stair, takes an extra 50 seconds to solve the Times crossword the next morning (even resorting to the dictionary) and Drumknott notes that he seems unusually talkative, though no less cogent.