I was reading some draft correspondence today, and had a mildly allergic reaction to seeing the word "unsatiable." I made the author change it to "insatiable." Here is the context: She is an unsatiable learner. Afterwards, I broke out the very large Webster's English Dictionary in the office and to my surprise found that "unsatiable" was in there as well; however, it referred specifically to "insatiable" for the definition. Try as I might, I was unable to pinpoint if there is actually any difference between the two words beyond frequency of usage. Is there really any difference between the two words or am I just being pedantic? In my opinion, "insatiable" is more acceptable due to its fidelity to its Latin roots, but it also seems to imply an ongoing desire. Do I have a point, or am I simply going with "insatiable" because it is more familiar? Thanks in advance for any help.