It would translate to mean stiff behavior or manners. You can try saying
Use the word decorous just as you would use the word 'proper'
"Members of the diplomatic corps are expected to behave in a stiffly decorous manner."
(Decorous - characterized by dignified propriety in conduct, manners, appearance, or character) Example: "Members of the diplomatic corps are expected to behave in a decorous manner."
The word "decorous" describes good taste and proper etiquette. An example of a sentence using the word "decorous" is "The diplomats were decorous at all times during their visit to the embassy. "
John stiffly sat next to me.
Decorous is, essentially, dignified. An example sentence would be: He was feeling very decorous that day in his new suit.
i so decorus when the teacher ask me a question.
Use the word decorous just as you would use the word 'proper'.Example: Bob has very decorous (a.k.a. proper) behavior when dining with the beaver weasels in Canada.
No, the word 'stiffly' is not a noun at all.The word 'stiffly' is the adverb form of the adjective 'stiff'.The noun form of the adjective stiff is stiffness, a concrete noun, a word for a physical quality.
Primly
Of sober or serious mien; composed and decorous in bearing; of modest look; staid; grave., Affectedly modest, decorous, or serious; making a show of gravity., To look demurely.
wavy
In keeping with good taste and propriety; polite and restrained.
In a stiff manner.