'HA' definitions:

Definition of 'HA'

From: WordNet
noun
(astronomy) the angular distance of a celestial point measured westward along the celestial equator from the zenith crossing; the right ascension for an observer at a particular location and time of day [syn: hour angle, HA]

Definition of 'Ha'

From: GCIDE
  • 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]