Complete round-the-world trip, or just part (5)
I believe the answer is:
orbit
'part' is the definition.
(orbit is a kind of part)
'complete round-the-world trip' is the wordplay.
I cannot quite understand how this works, but
'round' could be 'orb' and 'orb' is found in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is found in the answer.
A single letter 'i' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'or just' acts as a link.
Can you help me to learn more?
(Other definitions for orbit that I've seen before include "Planet's course" , "Field of influence" , "Path eg of heavenly body" , "Area of influence - eye socket" , "Circumnavigate" .)