Greek letter that sounds like the end of 16-, 22-, 36-, 47- or 58-Across 3 letters

Crossword clues for Greek letter that sounds like the end of 16-, 22-, 36-, 47- or 58-Across 3 letters:

RHO: Greek letter that sounds like the end of 16-, 22-, 36-, 47- or 58-Across