lade vs overburden

lade

verb
  • To fill or load (related to cargo or a shipment). 

  • To transfer (molten glass) from the pot to the forming table, in making plate glass. 

  • To use a ladle or dipper to remove something (generally water). 

  • To weigh down, oppress, or burden. 

  • To admit water by leakage. 

noun
  • The mouth of a river. 

  • Water pumped into and out of mills, especially woolen mills. 

  • A load. 

overburden

verb
  • To overload or overtax. 

noun
  • A sterile stratum that lies above the stratum being investigated 

  • The rock and subsoil that lies above a mineral deposit such as a coal seam. 

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