Near middle of pub, almost horizontal (7)

'horizontal' is the definition.
Both the definition and answer are adjectives.
Perhaps they are linked in a way I don't understand?

'near middle of pub almost' is the wordplay.
'near' says to put letters next to each other.
'middle of' becomes 'lying' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'pub' becomes 'inn' (an inn is a type of pub).
'almost' means to remove the last letter (almost the whole word is kept).
'inn' with its last letter removed is 'in'.
'lying' put after 'in' is 'INLYING'.

Can you help me to learn more?