What does the "Ice" word means in terms of Netrunner's Lore?
According to the original Netrunner rulebook (and as recorded in the Wiki ):
The corps in Netrunner view it as an acronym for Intrusion Countermeasure Electronics.
The runners view it as an acronym for Insidious Cortical Electrocution.
The original rulebook included it in the corp (runner) glossary thus:

Ice: A program that protects our data forts from intrusion. An acronym for &quot;intrusion countermeasures electronics.&quot; (An acronym for &quot;insidious cortical electrocution.&quot;)