In short, the lexicon is:
- Formulaic: it relies on partially fixed expressions and highly probable word combinations
- Idiomatic: it follows conventions and patterns for usage
- Metaphoric: concepts such as time and money, business and sex, systems and water, all share a large portion of the same vocabulary
- Grammatical: it uses rules based on sampling of the Lexicon
- Register-specific: it uses the same word differently and/or less frequently in different contexts
A major area of study, psycholinguistics and neurolinguistics, involves the question of how words are retrieved from the mental lexicon in online language processing and production. For example, the cohort model seeks to describe lexical retrieval in terms of segment-by-segment activation of competing lexical entries.