I have observed some mistakes or maybe called blunders in the usage of word "cog" joined with letters to make words.

Though the words made or built by using the word cog like "incognito" or "cognition" deals with concepts relevant to mind and knowledge, there's not a single hint or form or slang in the list of "cog" word's meaning that suggests "brain" or "mind" as one of it's meaning or related meaning.

I have searched many popular online wikis and vocabularies but all failed to establish relation between cog and mind and still use the words "incognito" or "cognizance" to refer to mind-related scenarios.

Can someone clarify or shed light on this mistake and how it can be rectified ?

  • 3
    'Cog' is not a root. 'Cognition' -> co + gnoscere. Commented May 30, 2020 at 19:49
  • Google cognition etymology.
    – Hot Licks
    Commented May 30, 2020 at 20:04
  • And cog is from Middle English, probably related to Swedish kugge and Norwegian kug.
    – GEdgar
    Commented May 30, 2020 at 20:06

2 Answers 2


The root is not cog, but co+gno:


to know," from Latin cognoscere "to get to know, recognize," *from assimilated form of com "together" (see co-) + gnoscere "to know," from PIE root gno- "to know."


  • Oh I didn't knew about that, thanks.
    – Vicky Dev
    Commented May 30, 2020 at 19:56
  • 3
    To your list of "popular online wikis" you should add Etymonline.
    – GEdgar
    Commented May 30, 2020 at 20:07
  • 1
    PIE *gno- is also the basis of English know. The original *g changed to k by Grimm's Law, and then later initial kn- clusters like the ones in knife and know dropped the stop and kept the nasal. Commented May 30, 2020 at 21:22

As a follow-on to user121863's answer, one must constantly remember that English is a creole (simplified mashup of) of Anglo-Saxon and French, with half taken from Latin via Old French. Another 10% is taken straight from Latin, and 20% from other languages.

For example, "Fur" and "fury" are pronounced so differently because one is Germanic via Old French, and the other is Latin via Old French. And "fir" is via Old Norse!!

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