I am not pulling your wible wobl. It's what we use in the west, the north actually have a far worse word for it which I am not going to write on here, I'm sure google will find it for you :)
I had some sglodion tonight.
Not sure what part of Wales your tutor is from, but there are many phrases and saying that are area specific, North and West are the main chunks of remaining Welsh speakers, and there are huge differences in dialect and more again as you go east into the Vallyes.
You may find this amusing :) I personally use 90% of these.
http://www.walesonline.co.uk/news/wales-news/gallery/24-welsh-words-phrases-just-6387577
Oh ok - I thought maybe it was a dialect thing, thanks for clarifying. Thanks for the link too, at least I can feel I have accomplished the spreading of the welsh language by referring to my friends as being as useful as a fart in a jam pot (in English) :))