Do you know the meaning of o-?
A blood type that has no antigens. It lacks the A, B and Rh factors on the blood cells. It is the universal donor for blood and can give blood to any blood type, but can only receive O- blood.
Word in 2 letters.
This definition of the word o- is from the Wiktionary, where you can also find the etimology, other senses, synonyms, antonyms and examples.
The word o- has 7 anagrams.
The word o- is a palindrome: it can be read backwards.
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Please note: the Wiktionary contains many more words - in particular proper nouns and inflected forms: plurals of nouns and past tense of verbs - than other English language dictionaries such as the Official Scrabble Players Dictionary (OSPD) from Merriam-Webster, the Official Tournament and Club Word List (OTCWL / OWL / TWL) from the National Scrabble Association, and the Collins Scrabble Words used in the UK (about 180,000 words each). LotsOfWords knows 480,000 words.