Some words change meaning based on how they are used, spelled, or punctuated. Naturally these distinctions are difficult for computers to recognize. Heteronyms, Homonyms, Contronyms, Capitonyms, and Acronyms are lesser-known nyms that confuse search engines.

• Heteronyms are words that are spelled the same, but change meaning based on pronunciation.
  • wind WHINEd - to coil up; WINd - the blowing air.
• Homonyms are words that sound the same but have different spellings and meanings.
  • acts things done / ax chopping tool
• Contronyms are words with identical spellings but contradictory meanings based on usage.
  • cool: positive sense (cool web-sites) vs. negative sense (cool reception);
• Capitonyms are words that change meaning when capitalized.
  • To polish piles of Polish brass.
• Acronyms are words created from the beginning initials of a group of descriptive words.
  • RADAR: RAdio Detection And Ranging.