A little bit of atmosphere picked up among oceanographers (5)
I believe the answer is:
argon
'a little bit of atmosphere' is the definition.
Although both the answer and definition are singular nouns, I don't understand how one could define the other.
'picked up among oceanographers' is the wordplay.
'picked up' shows that the letters should be reversed in order.
'among' indicates the answer is hidden within the clue.
'nogra' is hidden within 'oceanographers'.
'nogra' back-to-front is 'ARGON'.
Can you help me to learn more?
(Other definitions for argon that I've seen before include "Inert gas, present in small amounts in the air" , "Gas used in electric lights" , "Inert gas used in light bulbs" , "Gaseous element" , "noble element" .)