A noun, singular, most often pronounced ‘fonz’. This generally just means an archival collection, so when an archival description is at ‘fonds-level’, it’s an overview without details of each individual item. Some archivists simply use the term ‘collection’, or treat the terms as interchangeable. But others reserve ‘fonds’ to distinguish a collection generated by a person, family, or organisation, as opposed to an ‘artificial’ collection, which has been gathered and arranged by a collector or a repository.
Sadly, the term ‘fonds’ does not seem to appear in this sense in the Oxford English Dictionary. The OED does include ‘fond’, meaning "source of supply, stock, store", which is apt in the sense of the archival collection providing a fund of data, which we can elaborate with metadata. But does anyone want to suggest some published examples to the OED for the archival use of the word? And can anybody guide us with the pronunciation?