Settler's unusual support structure (7)

I believe the answer is:
trestle
'support structure' is the definition.
'trestle' can be an answer for 'structure' (trestle is a kind of structure). I am not certain of the 'support' bit.
'settler's unusual' is the wordplay.
'unusual' indicates anagramming the letters.
'settler' anagrammed gives 'TRESTLE'.
Can you help me to learn more?
(Other definitions for trestle that I've seen before include "Support for table top" , "Simple table support" , "Letters about a table support" , "Framework to support a flat surface -- letters (anag)" , "Framework for holding a tabletop" .)
