If all anyone ever talks about is APIs in the web services sense then, yes, the definition of API has been narrowed. When everyone will assume you mean web serv

If all anyone ever talks about is APIs in the web services sense then, yes, the definition of API has been narrowed. When everyone will assume you mean web services API when you refer to an API and have to use extra words to describe non-web APIs then the definition has narrowed. That's how English works: the definitions of words depend on their usage and dictionaries describe how words are used. You even admitted "The pervasiveness of web apps and applications consuming web services means there's a lot of work involving web APIs" and "If your bread and butter is developing web services, you don't waste time with context-free definitions of your API" which is acknowledging the common use definition of API has morphed into Web API. It's only in the context of technical documents or documents that are explicitly referring to non-web APIs that use API and it is understood to mean something other than a web API.