Crash before guillotine came down? (4-2)
I believe the answer is:
head-on
'crash' is the definition.
Both the definition and answer are adjectives. Perhaps you can see a link between them that I can't see?
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for head-on that I've seen before include "Frontal, collision say" , "In direct confrontation" , "One had (anag.)" , "Collision happening in full-frontal way" , "In direct opposition" .)