Phil Sheu in ICSC2007 cfp described it as:
"The field Semantic Computing applies technologies in natural languageprocessing, data and knowledge engineering, software engineering, computer systems and networks, signal processing and pattern recognition, and anycombination of the above to extract, access, transform and synthesize the semantics (contents) of multimedia, texts, services and structured data."
Here is my take:
Semantic computing is a vision of computing based on semantics shared between machines and people. It supports and exploits intrinsic, intended, and emergent meanings (content) in all aspects of computing, encompassing programming, algorithms, information management, and human interactions within devices, as part of communications, and across the Web. Semantics involves the use of formal descriptions, languages, and models, often encoded in metadata, knowledge, and representation of agreements (as in ontologies) to capture the content of multimedia, texts, services, and structured data so that it may be extracted, shared, synthesized and transformed. Semantic techniques foster the development emerging forms of computing, such as semantic Web, and entirely new forms, such as bio-inspired computing, as well as enhance traditional techniques of information retrieval, management of data (including multimedia and multimodal) and artificial intelligence (e.g., natural language processing machine learning, and computational intelligence), leading to more efficient and scalable information processing and higher-quality computer-human interaction.
[1] mid 80s to early 90s: So far yet so Near, Schematic and Semantic Similarities between Database Objects
[2] early 90s to about 1998: Semantic Information Brokering, InfoHarness, InfoQuilt, OBSERVER