One booted and horsed, crossing over, would knee-length fit tight? (3,4,2,10)

'fit tight?' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'one booted and horsed crossing over would knee-length' is the wordplay.
I cannot really see how this works, but
'one' could be 'the' (both can introduce a definite example of something) and 'the' is found in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is found within the answer.
'over' could be 'on' (physically on top of) and 'on' is present in the answer.
'would' could be 'd' (as in 'we'd' - 'we would') and 'd' is located in the answer.
'length' could be 'ell' (I've seen this before) and 'ell' is found within the answer.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?