As found in Ingrid’s 2010 blog article about her visit to the Nam-Ban Go club in Madrid:
I also learned the word ‘pichones’ which means something like ‘pigeon’ or ‘small chick’ and is a word used affectionately within the go club for beginning players or for not-so-good moves made by stronger players who should know better. (One of the women in the club had made a ‘Pichones’ t-shirt in the style of the famous Ramones logo for a team tournament – it was ace!)
The word pichones is actually plural. The singular is pichón.
Both pichón and English and French pigeon, as well as Italian piccione are – by the way – derived from Latin pípio, of onomatopoeic origin.