concubine vs steady

concubine

noun
  • A slave-girl or woman, kept for instance in a harem, who is held for sexual service. 

  • A sexual partner, especially a woman, to whom one is not or cannot be married. 

  • A woman who lives with a man, but who is not a wife. 

steady

noun
  • A prostitute's regular customer. 

  • A rest or support, as for the hand, a tool, or a piece of work. 

  • A regular boyfriend or girlfriend. 

adj
  • Smooth and not bumpy or with obstructions. 

  • Regular and even. 

  • Constant in feeling, purpose, or pursuit; not fickle, changeable, or wavering; not easily moved or persuaded to alter a purpose; resolute. 

  • Firm in standing or position; not tottering or shaking; fixed; firm. 

  • Slow. 

verb
  • To become stable. 

  • To stabilize; to prevent from shaking. 

particle
  • Aspect marker indicating consistency or intensity. 

adv
  • To row with pressure at a low stroke-rating, often 18 strokes per minute. 

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