Texan can brush over preposterous hat (8)
I believe the answer is:
bathroom
'texan can' is the definition.
'bathroom' can be an answer for 'can' (synonyms). I am unsure of the 'texan' bit.
'brush over preposterous hat' is the wordplay.
'brush' becomes 'broom' (I've seen this before).
'over' indicates putting letters inside.
'preposterous' indicates anagramming the letters.
'hat' anagrammed gives 'ath'.
'broom' going around 'ath' is 'BATHROOM'.
Can you help me to learn more?
(Other definitions for bathroom that I've seen before include "It has washing and toilet facilities" , "Usually the smallest room" , "Where to go" , "Abhor Tom (anag)" , "WC" .)