Inelegant tiers arranged as part of digestion (5,9)
I believe the answer is:
large intestine
'part of digestion' is the definition.
'large intestine' can be an answer for 'part' (large intestine is a kind of part). I am unsure of the 'of digestion' bit.
'inelegant tiers arranged' is the wordplay.
'arranged' is an anagram indicator (letters rearranged).
'inelegant'+'tiers'='ineleganttiers'
'ineleganttiers' is an anagram of 'LARGE INTESTINE'.
'as' acts as a link.
Can you help me to learn more?
(Other definitions for large intestine that I've seen before include "part of digestive system" , "this processes waste" , "food processor" , "Part of one's innards" .)