bulla vs calyx

bulla

noun
  • In ancient Rome, a kind of amulet or boss. 

  • A rich Jamaican cake made with molasses and spiced with ginger and nutmeg. 

  • A blister, vesicle, or other thin-walled cavity or lesion, as 

  • (usually and especially) Such a blister that is more than 5 mm in diameter. 

  • A clay envelope or hollow ball, typically with seal impressions or writing on its outside indicating its contents. 

  • Later, a handwritten document from the papal chancellery. 

  • The tympanic part of a temporal bone (having a bubble-like appearance) 

calyx

noun
  • The crown containing the viscera of crinoids and similar echinoderms, entoprocts, and the polyps of some cnidarians. 

  • A chamber in the mammalian kidney through which urine passes. 

  • The outermost whorl of flower parts, comprising the sepals, which covers and protects the petals as they develop. 

  • A flattened cap of neuropil in the brain of insects. 

  • A funnel-shaped expansion of the vas deferens or oviduct of insects. 

How often have the words bulla and calyx occurred in a corpus of books? (source: Google Ngram Viewer )