Thank you, I enjoyed your illuminating comments, and for the search phrase "semantic shift". I should have been more cognizant of metaphorical extension, having recently read [0] which claims "tall" went from "swift" to "vertically large" via "skillful" ("tall of hand") then "exaggerated" ("tall story").

[0] http://theconversation.com/five-words-that-dont-mean-what-yo...