An Australian colloquialism; describing someone intellectually impaired or moronic.
In the case of this phrase, the term "
roo" is an abbreviation for kangaroo, an Australian marsupial.
Used emphatically, the phrase is sometimes amended to "a few
roos loose in the top paddock".
To have a
roo loose in the top paddock:
After John spent all those years on
weed, he talked liked he had a
roo loose in the top paddock.