1 definition by kldsjiaehr787

Top Definition
1. An exstremely unattractive or "undateable" guy
2. Someone that one must avoid flirting with at all costs
3. Male who tends to spend most time alone on the computer
4. Opposite of a jackaroo
Girl #1: Eww! Rachel check out that jillaroo!
Girl #2: Yea Kaitlin, he's totally undateable!
by kldsjiaehr787 February 13, 2009

Mug icon
Buy a Jillaroo mug!