[...] we can easily restate the common understanding of the notion "lexically related": (7) X and Y are lexically related if X is derived from Y by a morphological rule, or if [immagine] where Y is a unit (or stage) in the derivation of X.
- Williams (2004), a pag.206

[...] we have proposed a revised notion of "lexically related" which says that suppressing or varying any head, or the nonhead, of a word defines a dimension along which that word may be related to other words.
- Williams (2004), a pag.225

In writings on morphology (e.g. [Aronoff, M., 1976, "Word Formation in Generative Grammar", MIT Press, Cambridge] or Selkirk (forthcoming)) there is an implicit use of the notion "lexically related". Although there is no explicit definition of this term, its components are clear: two lexical items are related if they share some morphemes, and if they share some element of meaning.
- Williams (2004), a pag.204