Nausea, oddly, overwhelming head of RTÉ, when they get the elbow? (5)
I believe the answer is:
nudge
'the elbow?' is the definition.
(I've seen this before)
'nausea oddly overwhelming head of' is the wordplay.
'oddly' means one should take alternating letters (letters in odd-numbered positions).
'overwhelming' means one lot of letters goes inside another.
'head of' becomes 'dg' (I can't explain this - if you can you should believe this answer much more).
The alternating letters of 'nausea' are 'nue'.
'nue' going around 'dg' is 'NUDGE'.
'rte when they get' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for nudge that I've seen before include "Jogger" , "Push with the elbow" , "Gentle poke with elbow" , "Facility of pinball machine" , "A gentle reminder?" .)