V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

SIA
       Semiconductor Industry Association (org., USA)


The Free On-line Dictionary of Computing (30 December 2018):

Serial Interface Adaptor
SIA

   (SIA) The Ethernet driver chip used on a Filtabyte
   Ethernet card.


Hitchcock's Bible Names Dictionary (late 1800's):

Sia, moving; help