robust vs soft

robust

adj
  • Requiring strength or vigor. 

  • Sensible (of intellect etc.); straightforward, not given to or confused by uncertainty or subtlety. 

  • Designed or evolved in such a way as to be resistant to total failure despite partial damage. 

  • Not greatly influenced by errors in assumptions about the distribution of sample errors. 

  • Resistant or impervious to failure regardless of user input or unexpected conditions. 

  • Of an individual or skeletal element: strongly built; muscular; not gracile. 

  • Violent; rough; rude. 

  • Evincing strength and health; strong; (often, especially) both large and healthy. 

soft

adj
  • Lacking strength or resolve; not tough, wimpy. 

  • 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. 

  • 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. 

noun
  • A soft sound or part of a sound. 

  • A soft or foolish person; an idiot. 

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