Doddery uncle getting on, eating hospital meal (8)
I believe the answer is:
luncheon
'meal' is the definition.
(luncheon is a kind of meal)
'doddery uncle getting on eating hospital' is the wordplay.
'doddery' indicates an anagram.
'getting' is a charade indicator (letters next to each other).
'eating' means one lot of letters goes inside another.
'hospital' becomes 'h'.
'uncle'+'on'='uncleon'
'uncleon' with letters rearranged gives 'lunceon'.
'lunceon' enclosing 'h' is 'LUNCHEON'.
(Other definitions for luncheon that I've seen before include "fare at one?" , "Midday meal" , "part of formal board" , "midday menu" , "formal occasion" .)