It's not an idiom - it's a description of what happens when you get nervous and excited. Your legs feel wobbly and you might even fall over because your knees get weak and collapse underneath you.
It is not an idiom, it means your nose is itching.
idiom means expression like a page in a book
Simply its mean a bully.
Faint means weak or not strong. The heart is considered the emotional organ so someone faint at heart would be emotionally weak.
I think it means that that person agrees with that others persons idiom and that it fit that question that the teacher or whoever asked that question.
no
love or lust
The idiom "dream on your knees" typically means to pray or hope for something strongly, often in a humble or earnest manner. It can also suggest seeking guidance or support from a higher power.
Susan had to be put into braces due to her weak knees.
Weak Knees - 1927 was released on: USA: 20 June 1927
Weak Knees - 1925 was released on: USA: 1 February 1925
It means you like the person.
deadpool
The cast of Weak Knees - 1925 includes: Cliff Bowes Virginia Vance
The cast of Weak Knees - 1927 includes: Henry Roquemore Lewis Sargent Wanda Wiley
It can be literally repairing breaks or weak spots in a fence, or it can be an idiom for repairing a "broken" friendship or other relationship.
It means that you are very weak (weaker than a flea on a tread mill).