Up in Orient travelling? That's rash (8)
I believe the answer is:
eruption
'that's rash' is the definition.
(synonyms)
'up in orient travelling?' is the wordplay.
'in' means one lot of letters goes inside another.
'travelling?' indicates an anagram.
'orient' is an anagram of 'ertion'.
'up' placed inside 'ertion' is 'ERUPTION'.
(Other definitions for eruption that I've seen before include "Spot or rash appearing suddenly on the skin" , "The action of a volcano" , "Volcanic outpouring" , "Rash - outburst" , "Exploding" .)