Sounds correct Im wondering if it instead comes from latin infact in italan witch is the most similar language we have the same word grave (with a different pronunciation ) to mean something important (not grave something not that important ) but grave its also an old word meaning something heavy like in old physics experiments … So maybe it became to be as something like it’s not a weight that heavy for me to carry if u don’t do this thing … more tied to the metaforical uncomfortableness given by a heavy weight … feel free to correct me I have never done latin at school … ( fun fact Yes more Italian than u think has done at least 5 years of latin )
Coming from French, grave means a low note all the way to the left on the piano, or a significant negative adjective. For example, an injury can be “grave” as in it can be significant, like losing a finger. Breaking a nail wouldn’t be “grave”.
I think your description of assigning weight to a matter is spot on.
Yeah we use it for the piano too … it would be cool to take into comparison the different pronunciation … its interesting how we have been able to pass between cultures a specific order of characters with an associated meaning but everyone chose it’s pronunciation… in italian is so different … (From the English one)