[...] the lexical component [...] contains a list of freely occurring lexical items (which I will assume to be words, in English). We may call this the "dictionary" (or "lexicon", in the restricted sense).
- Selkirk (2004), a pag.282

The meaning of a simple word is totally unpredictable, and even in the case of complex words the meaning often cannot be predicted on the basis of its component parts. The conclusion is that a word and its (idiosyncratic) meaning must be paired in a list; that list is the dictionary.
- Selkirk (2004), a pag.283