As noted above, in each entry, and indeed with each definition within an entry, an original source is cited. It is emphasised again that the definition which accompanies this citation is not necessarily the same entry verbatim that appears in that citation. In many cases, the definition in The Williams Dictionary has been changed slightly from that which appeared in the named work, either for greater consistency, greater clarity or to increase the contextual element related to biomaterials science; in such cases, no explanation is given. In some other cases, a more substantial change is made, which is explained in a note, while in a small number, a commentary is given which draws attention to difficulties with the quoted definition and suggests that this definition is not used, or that an alternative is preferred.

Since it was clearly not the intention to invent new definitions where perfectly adequate definitions already existed, or ones which could readily be modified were available, almost 90% of the definitions in The Williams Dictionary have been derived from or are based upon these original sources. For the remainder, either a satisfactory original definition could not be found from the range of sources available, or the word was sufficiently new within the specific area of biomaterials science that the scientific community had yet to evolve a satisfactory definition. In these cases, marked by the citation ‘Williams’, I have provided my own version of a definition, suitably annotated by supplementary comments where appropriate.