iPhone siri name meaning

Just to clarify, Siri Inc. is the company that Apple acquired in April of 2010 [1]. Siri Inc. developed Siri, a personal assistant application that was available for awhile on Apple's App Store before the acquisition [2]. After integrating it into the 4S, Apple retained its original name rather than rebrand it.

I haven't found any concrete information on the origin of the name Siri pertaining to Siri Inc. other than what I just learned about Siri being a spinoff of SRI from Brian Roemmele's answer. "Siri" may've just been a casual way they referred to SRI internally.

An underlying meaning of the word may have also been a factor in their decision. Googling I found a couple meanings of 'Siri':

• The name Siri is of Scandinavian origin and the meaning of Siri is "beautiful victory".  [3]
• 'Siri' in the South-Indian language Tamil means 'to smile'. (courtesy of Praveen Rajaretnam's comment below)
• [Siri is] an object-oriented constraint language using a single abstraction mechanism developed by Bruce Horn of CMU in 1991. Siri is a conceptual blend of BETA and Bertrand. It is similar to Kaleidoscope. [4]

The fact that Siri was unveiled to the world with the iPhone4S may also have had some weight in the decision to retain the Siri name. i.e. There's the iPhone 4, then there's the iPhone4S - which would people most commonly associate with Apple's brilliant new Siri voice recognition assistant?