Crossword Genius

Nigerian playing bingo has crossed out number (4)

Ross

I believe the answer is:

igbo

I'm a little stuck... Click here to teach me more about this clue!

'nigerian' is the definition.
(I know that Igbo is a type of nigerian)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for igbo that I've seen before include "Nigerian language" , "people abroad" , "language in Nigeria" .)

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