under the rose

Etymology
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Adverb

 * 1)  In secret; secretly, privately.
 * 2) * 1861, Dante Gabriel Rossetti, quoted by Fiona MacCarthy (2011) in The Last Pre-Raphaelite, Faber, ISBN 978-0-571-22861-4, page 130:
 * We are organising (but this is quite under the rose as yet) a company for the production of furniture and decoration of all kinds, for the sale of which we are going to open an actual shop!
 * We are organising (but this is quite under the rose as yet) a company for the production of furniture and decoration of all kinds, for the sale of which we are going to open an actual shop!