Revered symbol the Egyptians originally found in cat (5)
I believe the answer is:
totem
'revered symbol' is the definition.
(I've seen this before)
'the egyptians originally found in cat' is the wordplay.
'originally' indicates taking the first letters.
'found in' means one lot of letters goes inside another.
'cat' becomes 'tom' (a tom is a male cat).
The initial letters of 'the egyptians' is 'te'.
'te' put into 'tom' is 'TOTEM'.
(Other definitions for totem that I've seen before include "Object believed to have spiritual significance" , "Symbolic pole" , "Representative of family" , "token" , "charming symbol, say" .)