Traveller to welcome Terry inside (5)

I believe the answer is:

comet

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'traveller' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.

'welcome terry inside' is the wordplay.
'inside' indicates the answer is hidden within the clue.
'COMET' is hidden within 'welcome terry'.

'to' is the link.

Can you help me to learn more?

(Other definitions for comet that I've seen before include "Halley's space traveller?" , "Tailed space traveller" , "Celestial orbiter" , "Rudolph's companion" , "Dancer's colleague" .)

I've seen this clue in The Guardian.

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