Hike starts in The Rip and ends in the outback (4)
I believe the answer is:
trek
'hike' is the definition.
(trekking is a kind of hiking)
'starts in the rip and ends in the outback' is the wordplay.
'starts in' says to take the initial letters.
'and' is a charade indicator (letters next to each other).
'ends in' says to take the final letters.
The first letters of 'the rip' is 'tr'.
The final letters of 'the outback' are 'ek'.
'tr'+'ek'='TREK'
(Other definitions for trek that I've seen before include "Long hard journey on foot" , "Great journey" , "A long arduous walk" , "Long walk in the mountains?" , "A long arduous march" .)