glib vs tip of the iceberg

glib

verb
  • To make smooth or slippery. 

noun
  • A mass of matted hair worn down over the eyes, formerly used in Ireland. 

adj
  • Snarky or unserious in a disrespectful way. 

  • Having a ready flow of words but lacking thought or understanding; superficial; shallow. 

  • Artfully persuasive but insincere in nature; smooth-talking, honey-tongued, silver-tongued. 

tip of the iceberg

noun
  • A small indication of a larger possibility; the first part encountered of a problem that is much bigger than it seems. 

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