Old politician dumps wife by hotel on a trip (4)
I believe the answer is:
high
'on a trip' is the definition.
(I've seen this before)
'old politician dumps wife by hotel' is the wordplay.
'old politician' becomes 'Whig' (Whigs were a historical British political party).
'dumps' indicates named letters should be taken away.
'wife' becomes 'w' (abbreviation).
'by' says to put letters next to each other.
'hotel' becomes 'h' (phonetic alphabet: alpha, bravo, charlie etc.).
'whig' with 'w' taken away is 'hig'.
'hig'+'h'='HIGH'
(Other definitions for high that I've seen before include "Far above ground level" , "Relatively great or specific elevation" , "on a trip" , "Way up" , "Outstanding feature" .)