I was asked recently about how I would analyze the word <curious>. My initial hypothesis before seeking evidence from related words was the following:
cure/ + i + ous --> curious
I did not think that my proposed base was the free base <cure> for "a cure for the common cold". Instead I was assuming it was a bound base. The common <-ous> suffix and <-i-> connecting vowel letter struck me as providing the most likely analysis.
Following the 4 questions, I knew I needed some evidence from etymological and morphological relatives to test my hypothesis.
Of the top of my head, I could not think of any morphologically related words that did not have the <-ious> affixal construction. (with the structure<-i + ous>). So I wen tto Etymlonline and found this entry:
mid-14c., "eager to know" (often in a bad sense), from Old French curios "solicitous, anxious, inquisitive; odd, strange" (Modern French curieux) and directly from Latin curiosus"careful, diligent; inquiring eagerly, meddlesome," akin to cura "care" (see cure (n.)). The objective sense of "exciting curiosity" is 1715 in English. In booksellers' catalogues, the word means "erotic, pornographic." Curiouser and curiouser is from "Alice in Wonderland" (1865).
I found a lot about this fascinating. First I noted that originally their was a negative connotation to this word that is not so prominent in today's usage. Secondly, I do see some sort of signal that this <curious> might be related to the free base <cure> after all!
However, my understanding of Latin structure and etymology is not enough for me to use this etymological information to come to any strong conclusions about the current synchronic morphological structure of <curious>. I'll share what I'm thinking, and see if anyone out there can help me understand better.
When I see the Latin word curiosus which is a root of our current English word <curious>, I know there is a Latin suffix '-us' so I could write that suffix like this: curios(us).
I don't know about any Latin structure to explain the letters "ios" however.
Perhaps most importantly I don't know how to underestand the relationship between the Latin curiousus for "careful, inquiring eagerly" and the Latin cura for "care". I'm wondering about Douglas's use of the word "akin" here. I don't know if this is the same as saying "related to" or if it signals some other sense. Regardless, the description is NOT that curiousus dervived from cura for "care".
Does this entry give me evidence that the English <curiosity> goes back to a Latin root cur(a) for "care"?
If so, I would think that I have etymological evidence for my hypothesized morphological analysis even if I can't find a morphological relative without the <-ious> affixal construction. I can see the spelling of the Latin stem cur- giving rise to the <cure> English base. But the semantic distance from "care" to what we have for <curious> is not obvious. However, that does not mean that there.
When I searched etymonline for "cura" that sense of "care" was obvious to all except <curious>, and the entry for this one was the only one with that descriptor "akin".
So for the moment I can treat <curious> as a base. I'm wondering if someone out there can help me understand the etymological relationship to the word <care> and if that relationship allows me to conclude that this is also the base of <curious>.