The Collaborative International Dictionary
knowledge worker
knowledge worker \knowledge worker\ n. A person whose occupation is predominantly concerned with generating or interpreting information, as contrasted with manual labor.
Wiktionary
knowledge worker
n. someone who works with information or data
Wikipedia
Knowledge worker
Knowledge workers are workers whose main capital is knowledge. Examples include software engineers, physicians, pharmacists, architects, engineers, scientists, public accountants, lawyers, and academics, whose job is to "think for a living".