On travelling transport or a plank (6)

I believe the answer is:

aboard

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'on travelling transport or' is the definition.
I can't tell whether this definition defines the answer.

'a plank' is the wordplay.
'plank' becomes 'board' (synonyms).
'a'+'board'='ABOARD'

Can you help me to learn more?

(Other definitions for aboard that I've seen before include "on a train, perhaps" , "in a car" , "On (eg, a ship)" , "on boat, perhaps" , "A poet penning nothing on vessel" .)

I've seen this clue in the Sydney Morning Herald.

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