ha-ha

I couldn't pass up this definition from Apple's Dictionary application:

ha-ha |ˈhä ˌhä; ˌhä ˈhä|

noun

a ditch with a wall on its inner side below ground level, forming a boundary to a park or garden without interrupting the view.

ORIGIN early 18th cent.: from French, said to be from the cry of surprise on suddenly encountering such an obstacle.

I guess the modern day version of a ha-ha would be oh-crap?