Ultimate in retro features in 50s lounge (4)
I believe the answer is:
loll
'lounge' is the definition.
(both can mean to sit in a relaxed way)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for loll that I've seen before include "lie and take it easy" , "Lie sprawled" , "Lean back in lazy and relaxed manner" , "Hang loose" , "Lounge - loaf" .)