Word Meanings and Implicospheres


Another post on word meanings.

One of my ongoing beliefs is that finding/making definitions of words doesn't work very well. Instead, a word tends to have a single "primary" meaning and an "implicosphere" of associated meanings: My understanding is that this mirrors how words develop, but I am not a linguist

Consider the word "sister" as an example.

The primary meaning is simple. My sister is
  1. A girl/woman who has the same mother and the same father as I do
The first level of implications is also pretty obvious. The term now can also refer to:
  1. A maternal half-sister, who has the same mother but a different father
  2. A paternal half-sister, who has the same father but a different mother
  3. A step-sister, who is not related genetically, but who's mother is married to my father or vice versa
  4. A sister-in-law (1), who is married to my brother
  5. A sister-in-law (2), who is the sister of my wife
  6. An adopted sister, who is not related genetically, but is raised as if she was the child of my parents
I am not sure if you can have a half- or step- adopted sister. My guess is that these just count as adopted sisters. I also assume that the wife of my adopted brother is just a sister-in-law, not an adopted sister-in-law.

Then the implications get a bit fuzzier. A sister could also be:
  1. An honorary sister, who is not related to me by blood or law, but whom I treat as a sister (except we would be allowed to marry if we wanted)
  2. Another (female) Christian, who I theoretically treat as if she was my sister (see Matthew 12:50, Mark 10:29-30, 1 Timothy 5:2, James 2:15-16)
  3. A wife (in ancient Egypt), presumably from the closeness of the relationship
  4. A nun, probably derived from #9
And probably more I don't know.

Coming up with a single definition to cover all these (and nothing else) would be nearly impossible. Listing them out takes quite a while, and seems a bit arbitrary. (These ones are related, but why can't I add something that isn't? #10 isn't related to #11.)

On the other hand, with my primary-implicosphere approach, I just need "#1 and thinks like it", with clarifying points as needed. We need the clarifying points anyway (dictionaries often have examples), so this seems an improvement.


  1. I believe the term "implicosphere" was coined by Douglas R Hofstadter in his essay "Variations on a Theme as the Crux of Creativity".
  2. A similar idea is discussed by Eliezer Yudkowsky here.


I got the following response from a linguist I know:
Taxonomies. Female of a certain relationship within the same generation. 8-11 are metaphorical in nature. Everything else is just compounding to be more specific about the exact nature of the relationship.

Kin terms are defined with respect to each other, but also to ego, the individual to whom the system is calibrated. Brother and sister are on the same generational level, with the same parents. Mother differs from, grandmother, daughter, and sister in generation, but in the same line of descent. In the compounded forms, half-sisters share one half of the sisterly relationship, with respect to parentage. In-laws bear a sisterly relationship within, at least in the past, legally recognized marriages. Adopted sisters hold the same relationship within the one generation, but do not share parents. In the metaphorical uses, they are simply female people within the same level of a hierarchy, not necessarily related to age.

Back to essays page
Back to home page