Hazel - as the third letter of the alphabet (a nice touch of Dwelly's) - is "Coll". He marks it as "obsolete". It can also mean "neck" or "destruction", but it doesn't mean "knowledge"! A "Cuil" without the accent mark, acc. to Dwelly, is short for "cuileag" and means "fly" - as in a housefly, or a fishing fly.
I get the idea that these characters don't actually SPEAK Gaelic . . . or even read it very well.
Thanks! I was at work and had only my electronic copies available.
Some sharp comments -- but I had to laugh a little at the post heading: our Gaelic society newletter is called "Am Bradan Fhiosa"