Canadian, British and American Spelling   Words Beginning with the Letter O    Home Page   Browse by First Letter   General Rules for Regional Differences   Basic English Spelling Rules   A Short History of English   Some Commonly Misspelled Words  A   B   C   D   E   F   G   H   I   J   K   L   M   N   O   P   Q   R   S   T   U   V   W   X   Y   Z  Search for Exact Word Any Part of Word Search tips [Less common, less "correct" or archaic variations are marked like this(var)] Canadian British American Notes ochre ochre ocher odour odor(var) odour odor but 'odorous' in all countries offence offense(var) offence offense offense often used in sports context in Canada; always offensive omelette omelet(var) omelette omelet omelette(var) optimization optimisation optimization(var) optimization optimize optimise optimize(var) optimize organization organisation organization(var) organization organize organise organize(var) organize oxidization oxidisation oxidization(var) oxidization oxidize oxidise oxidize(var) oxidize