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-itious

American  
  1. a compound suffix occurring in adjectives of Latin origin (adventitious ) and with adjectives, formed in Latin or English, associated with nouns ending in -ition (ambitious; expeditious ).


-itious British  

suffix

  1. having the nature of; characterized by

    nutritious

    suppositious

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of -itious

< Latin -icius or -īcius (as in adventitious ); and < Latin -itiōsus or -ītiōsus (as in ambitious )