Thank you Tdol.
As to the word "grave", I do see your sense about it, but in Merriam-Webster, it goes like this:
Main Entry: 4grave
Pronunciation: 'grAv, in sense 5 often 'gräv
Function: adjective
Inflected Form(s): grav·er; grav·est
Etymology: Middle French, from Latin gravis heavy, grave -- more at GRIEVE
1 a obsolete : AUTHORITATIVE, WEIGHTY b :
meriting serious consideration : IMPORTANT <grave problems> c : likely to produce great harm or danger <a grave mistake> d : significantly serious : CONSIDERABLE, GREAT <grave importance>2 : having a serious and dignified quality or demeanor <a grave and thoughtful look>
3 : drab in color : SOMBER
4 : low-pitched in sound
5 a of an accent mark : having the form ` b : marked with a grave accent c : of the variety indicated by a grave accent
But, on the other hand, as a native speaker, you are always right. I know a dicionary doesn't tell everything.
Thank you so much for your help.