liquid vs vowel

liquid

noun
  • Any of a class of consonant sounds that includes l and r. 

  • A substance that is flowing, and keeping no shape, such as water; a substance of which the molecules, while not tending to separate from one another like those of a gas, readily change their relative position, and which therefore retains no definite shape, except that determined by the containing receptacle; an inelastic fluid. 

adj
  • Belonging to a class of consonants comprised of the laterals and the rhotics, which in many languages behave similarly. 

  • Having sufficient trading activity to make buying or selling easy. 

  • Flowing or sounding smoothly or without abrupt transitions or harsh tones. 

  • Fluid and transparent. 

  • Flowing freely like water; fluid; not solid and not gaseous; composed of particles that move freely among each other on the slightest pressure. 

  • Easily sold or disposed of without losing value. 

vowel

noun
  • A letter representing the sound of vowel; in English, the vowels are a, e, i, o, u, and y. 

  • A sound produced by the vocal cords with relatively little restriction of the oral cavity, forming the prominent sound of a syllable. 

verb
  • To add vowel points to a consonantal script (e.g. niqqud in Hebrew or harakat in Arabic). 

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