drone vs soft

drone

noun
  • A humming or deep murmuring sound. 

  • One of the fixed-pitch pipes on a bagpipe. 

  • One who performs menial or tedious work. 

  • A person without the ability to think critically and independently, especially one who follows a group blindly; a non-player character. 

  • A remotely controlled aircraft, an unmanned aerial vehicle (UAV). 

  • A Toyota HiAce or a similar van, especially one used by Ugandan state agents to kidnap opposition members. 

  • A male ant, bee or wasp, which does not work but can fertilize the queen. 

  • A genre of music that uses repeated lengthy droning sounds. 

  • A low-pitched hum or buzz. 

verb
  • To speak in a monotone way. 

  • To produce a low-pitched hum or buzz. 

  • To kill with a missile fired by unmanned aircraft. 

soft

noun
  • A soft sound or part of a sound. 

  • A soft or foolish person; an idiot. 

adj
  • Of a ferromagnetic material; a material that becomes essentially non-magnetic when an external magnetic field is removed, a material with a low magnetic coercivity. (compare hard) 

  • Expressing gentleness or tenderness; mild; conciliatory; courteous; kind. 

  • Requiring little or no effort; easy. 

  • Voiced; sonant; lenis. 

  • Voiceless. 

  • Gentle. 

  • Lacking strength or resolve; not tough, wimpy. 

  • Low in dissolved calcium compounds. 

  • Smooth and flexible; not rough, rugged, or harsh. 

  • Easily giving way under pressure. 

  • Emulated with software; not physically real. 

  • Not likely to cause addiction. 

  • Not containing alcohol. 

  • Weak in character; impressible. 

  • Not harsh or offensive to the sight; not glaring or jagged; pleasing to the eye. 

  • Gentle in action or motion; easy. 

  • Incomplete, or temporary; not a full action. 

  • Effeminate. 

  • Of a market: having more supply than demand; being a buyer's market. 

  • softcore. 

  • Palatalized. 

  • Not bright or intense. 

  • Physically or emotionally weak. 

  • Foolish. 

  • Agreeable to the senses. 

  • Having a slight angle from straight. 

  • Made up of nonparallel rays, tending to wrap around a subject and produce diffuse shadows. 

  • Quiet. 

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