Second USA trip fresh in the mind (8)
I believe the answer is:
upstairs
'in the mind' is the definition.
(synonyms)
'second usa trip fresh' is the wordplay.
'second' becomes 's' (common abbreviation).
'fresh' indicates anagramming the letters.
's'+'usa'+'trip'='susatrip'
'susatrip' with letters rearranged gives 'UPSTAIRS'.
(Other definitions for upstairs that I've seen before include "Having taken steps to rise" , "On an upper floor" , "Mentally (colloquial)" , "On an upper storey" , "Above ground floor" .)