In artificial intelligence, an expert system is a computer system emulating the decision-making ability of a human expert. Wikipedia

Software which automates decision making Wikipedia Disambiguation

computer system that emulates the decision-making ability of a human expert Wikidata

A computer configuration of hardware and software that simulates the judgment and behavior of a human or an organization with extensive knowledge in a particular field, often by giving answers, solutions or diagnoses. OmegaWiki

A type of artificially intelligent software system, which stores expertise concerning some subject matter in a knowledge base and attempts to answer questions or solve problems in a manner which simulates the thought processes of a human expert. Wiktionary

Type of artificially intelligent software system. Wiktionary (translation)