it's complicated.
originally, in Latin, it does meant "tounge" - L. lingua "tongue," ,so when you say lingua latina you literally mean
Tongue Latina (at least in other languages - in Polish we certainly still use "tongue" if we mean "language)-
for example, when we say 'English language" the literal translation in Polish is "English tongue", but in Polish it makes sense.
It translates into 'language', of course, the tongue as a part of anatomy translates as "tongue".
btw, there is a phrase "mother tongue".
~ so, in Latin "tongue", then it evolved into Old French (O.Fr) "langage" - meaning "words, what is said, conversation, talk," - and such a kinda metaphorical meaning remained today.
as many many many words today.
take the word, say, "walk"
look how far it came from today's meaning
walk
O.E. wealcan "to toss, roll," and wealcian "to roll up, curl, muffle up," from P.Gmc. *welk- (cf. O.N. valka "to drag about," Dan. valke "to full," M.Du. walken "to knead, press, full," O.H.G. walchan "to knead," Ger. walken "to full"), perhaps ult. from PIE base *wel- "to turn, bend, twist, roll" (see
Walk | Define Walk at Dictionary.com
You simply can not compare. words evolved from gestures, btw, and pictures, not the other way.
Before the Word, There Was the Gesture | Wired Science | Wired.com
Previously dismissed 'doodles' in French caves could be man's very first attempts to write | Mail Online
It is very easy to understand this theory, and believe. When a group of different nationalities meet, and none speak the others language,
how do they communicate?
Fuzzy