Crib most ideas going round - oddly that's ground breaking (7)
I believe the answer is:
seismic
'crib most' is the definition.
Both the definition and answer are adjectives. Maybe you can see an association between them that I can't see?
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for seismic that I've seen before include "Relating to earthquakes" , "Caused by an earthquake" , "massive" , "Earthshaking" , "Resulting from earthquakes" .)