From Longman Dictionary of Contemporary EnglishOO1, o /əʊ $ oʊ/ noun (plural O’s, o’s) 1 SLA[countable, uncountable] the 15th letter of the English alphabet2 [uncountable] spokenHMN zero My phone number is six o four double two (=60422).3 [uncountable] a common type of bloodOO2 /əʊ $ oʊ/ interjection 1 ALused when praying to a god or, in the past, when speaking to someone in great authority O Lord, in you I put my trust.2 x-refanother form of oh
Examples from the Corpus
O• O Lord, hear our prayer.o'o' /ə/ preposition AL‘of’ written as people sometimes say it informally a drop o' whisky → o'clockExamples from the Corpus
o'• a cup o' coffeeOrigin O (1100-1200) Natural sound 