850: cygnet Apr 6, 2017
When diminutive suffixes are added to words in English, they tend to be specific to certain words. For instance, a young duck is a 'duckling', a young goose is a 'gosling', but a young cat is a 'kitten', not a 'catling', even though all of those words are of Germanic origins. Some words for animals do not even use suffixes, but employ adjectives like 'cub', though this is equally dependent on individual terms. The term for a young swan, 'cygnet' does not appear so use a diminutive suffix, but certainly does not use an adjective either (unless some people may prefer 'baby swan' for simplicity). While some terms for young animals, as with 'puppy' or 'baby' are completely separate that the word for the mature form, but 'cignet' does have a diminutive suffix after all. The word 'swan' comes from Old English, but the word 'cignet' comes from the Old French 'cigne' ('swan'), so the '-et' suffix, logically, is also from Romantic origins. This suffix is also present in 'budget' and 'ballet', also from French.