A very severe headache, as if an imaginary axe is "splitting your head in two".
Splitting Headache was created on 2005-07-12.
Splitting. I have a splitting headache.
I took the afternoon off work because I had a splitting headache.
My brother can be annoying at times. My brother gets on my nerves sometimes.
The Good Guys - 1968 The Splitting Headache 1-22 was released on: USA: 5 March 1969
splitting severe
a heart,lights,music,electromagnetic waves,your head [when you have a splitting headache]
It's not really an idiom. It means "what are you thinking about."
It is not an idiom, it means your nose is itching.
RFP is not an idiom. It's an abbreviation.
"Sieve" is not an idiom. See the related link.
It's not an idiom. It means the tip of your nostril.