As far as "the right height” (3)
I believe the answer is:
tor
'height' is the definition.
(I've seen this before)
'as far as the right' is the wordplay.
'as far as' becomes 'to'.
'the right' becomes 'r' (common abbreviation).
'to'+'r'='TOR'
(Other definitions for tor that I've seen before include "Feature of Dartmoor" , "rise" , "Rot on rocky peak" , "Rocky outcrop" , "Rot about the rocky height" .)