verb

• (intransitive, obsolete except figuratively) To burst into bloom; to flower.
  "The genus isis, or coral, in the order of zoophytes, or composite animals, efflorescing like vegetables, is an animal in the form of a plant, with a stony stem, jointed, and the joints longitudinally channelled, united by spongy or horny junctures, covered by a soft porous cellular flesh or bark, and having a mouth beset with oviparous polypes."
• (intransitive, figuratively) Of something hidden: to come forth, to emerge; also, to reach full glory or power.
  "These [God's promises], implanted in the soul of David, effloresced in the Psalms to that luxuriance and fruitfulness which have made them the delight and nourishment of all succeeding ages of the church, [...]"
• (intransitive, chemistry) Senses relating to chemistry.
  "This is the very caſe with the Pyrites that conſiſt only of iron and ſulphur; yet ſome of them, as we ſaid before, do not effloreſce ſpontaneouſly and turn to Vitriol."
• (intransitive, chemistry) Senses relating to chemistry.
  "The ſalts which effloreſce from old walls, are nitre more or leſs pure, quadrangular nitre, mineral alkali in abundance, more or leſs pure, and mixed with calcareous earth; [...]"