Not appearing in unusually cheap memorial (8)
I believe the answer is:
cenotaph
'memorial' is the definition.
(cenotaph is a kind of memorial)
'not appearing in unusually cheap' is the wordplay.
'appearing in' indicates putting letters inside.
'unusually' indicates anagramming the letters.
'cheap' anagrammed gives 'ceaph'.
'not' inserted into 'ceaph' is 'CENOTAPH'.
(Other definitions for cenotaph that I've seen before include "Monument to those killed in war" , "Monument to people whose remains are interred elsewhere" , "Tomb-like monument to people buried elsewhere" , "construction in Whitehall" , "War memorial" .)