High houses might start to shake (7)
I believe the answer is:
tremble
'shake' is the definition.
(synonyms)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for tremble that I've seen before include "Shiver or jerk quickly" , "Look nervous" , "get the shakes" , "Show fear" , "Shake - quiver" .)