See block (def. 21)
These Common Words Have Some Very Uncommon OppositesYou know up is the opposite of down, but do you know the antonyms of ambidextrous and placebo? English isn't always black and white.
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