from
The Collaborative International Dictionary of English v.0.48
Ha \Ha\ (h[aum]), interj. [AS.]
An exclamation denoting surprise, joy, or grief. Both as
uttered and as written, it expresses a great variety of
emotions, determined by the tone or the context. When
repeated, ha, ha, it is an expression of laughter,
satisfaction, or triumph, sometimes of derisive laughter; or
sometimes it is equivalent to "Well, it is so."
[1913 Webster]
Ha-has, and inarticulate hootings of satirical rebuke.
--Carlyle.
[1913 Webster]