The origin and history of words is studied by a discipline known as etymology, which determines the language in which the word originated as well as the evolution of this. Due to this, in a dictionary entry including online dictionary entries, you should take a look at the section of "Etymology" to understand the origin of the word.
According to this, in the case of the entry presented to know more about the origin fo the word, the reader can read the section "etymology" and then if possible click on the link "lingua" in this section because this is the word in Latin that originated the word in English "language", and therefore by clicking in "lingua" you can get more information about the origin and evolution of the word.
For the sign you place your dominant hand into your non- dominant hand and have your dominant hand move from your non- dominant hand to your face near your face. A good way t remember it is to think of it as taking the knowledge from the book (non- dominant hand) and removing it and placing it into your brain.
Synecdoche- Specifically, it is defined as a figure of speech in which a word or phrase with a literal meaning that refers to a part of something is used figuratively to represent the entirety of that thing.
