Bachelor, one on board, finds footing (5)
I believe the answer is:
basis
'footing' is the definition.
(I know that footing can be written as basis)
'bachelor one on board' is the wordplay.
I cannot quite see how this works, but
'bachelor' could be 'ba' (Bachelor of Arts) and 'ba' is present in the answer.
'one' could be 'i' (Roman numeral) and 'i' is present in the answer.
'on board' could be 'ss' (I've seen this in other clues) and 'ss' is found within the remaining letters.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).
'finds' acts as a link.
Can you help me to learn more?
(Other definitions for basis that I've seen before include "Foundation of a theory or process" , "Underlying support (for an idea)" , "Principal element" , "Ground, foundation" , "Groundwork, foundation" .)