What does O'Nee mean in Swahili?

O'nee is not a Word in Swahili, even by alternative spellings. The apostrophe is used in Swahili only in some Words after the letters ng, e.g., ng'ombe, cattle. But it does not appear in some other Words with ng, e..g., ngoma, drum or dance. The apostrophe indicated a slightly different pronunciation that a western listener might not even hear.