Etymology 1
From full + blow (“to blossom”).
Adjective
full-blown (comparative more full-blown, superlative most full-blown)
- (figurative) Completely developed or formed.
- Synonyms: full-fledged, full-bore
We are in the midst of a full-blown crisis.
2012, Lydia Pyne, Stephen J. Pyne, The Last Lost World, Penguin, →ISBN:The Little Ice Age that chilled Europe […] should, according to past precedents, have snowballed into a full-blown ice age.
- At the peak of blossom; ripe.
The trees in the garden were resplendent with full-blown white gardenias.
1785, William Cowper, “Book I. The Sofa.”, in The Task, a Poem, […], London: […] J[oseph] Johnson; […], →OCLC, page 3:There might ye ſee the pioney ſpread vvide, / The full-blovvn roſe, the ſhepherd and his laſs, / Lap-dog and lambkin vvith black ſtaring eyes, / And parrots vvith tvvin cherries in their beak.
1814 May 9, [Jane Austen], chapter VII, in Mansfield Park: […], volume (please specify |volume=I to III), London: […] [George Sidney] for T[homas] Egerton, […], →OCLC:“Fanny has been cutting roses, has she?” “Yes, and I am afraid they will be the last this year. Poor thing! She found it hot enough; but they were so full-blown that one could not wait.”
1891, Thomas Hardy, chapter L, in Tess of the d’Urbervilles: A Pure Woman Faithfully Presented […], volume (please specify |volume=I to III), London: James R[ipley] Osgood, McIlvaine and Co., […], →OCLC:Above, Jupiter hung like a full-blown jonquil, so bright as almost to throw a shade.
Etymology 2
From full + blow (“to produce an air current”).