Doona is Australian slang for quilt or blanket.
It was 7º so he decided to walk around the house wrapped in a doona rather then put clothes on.
The doona differs fron the quilt, eider-down and duvet in that it has a removable, washable cover thus eliminating the need for cover sheet and blankets.
The word is Swedish implying that it is filled with down, although the great technical advance was that it was actually filled with non-allergenic polypropeline padding. The name comes from an advertising campaign in the 1960's in Australia by the furniture company, Ikea.
"Now at your Ikea store, the latest for the bedroom - the doona! Just the thing to go with your futon."
The warm thing that you snuggle up under when it's cold.
Person One: It's so cold, I can feel my toes freezing!
Person Two: Yeah, I wish I could just go and lie underneath my doona and sleep.
one of the funnyest words in english history, along with omnibus and fork