candlestick vs thermionic valve

candlestick

noun
  • A holder with a socket or spike for a candle. 

  • A gymnastics move in which the legs are pointed vertically upward. 

  • A color-coded bar showing the open and closing prices of a stock on a candlestick chart. 

verb
  • To catch on fire, so that the chute resembles a tapered candle with a flame on top. 

  • To adorn with candlesticks. 

  • To analyze stock behavior using Japanese candlestick charts. 

  • To form a tall, thin, tapering shape similar to a candle. 

thermionic valve

noun
  • An electronic device incorporating electrons from a glowing cathode inside an evacuated glass tube, functioning as a switch, amplifier etc. 

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