Wobbly thing lets in winter air (6,5)
I believe the answer is:
silent night
'winter air' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'wobbly thing lets in' is the wordplay.
'wobbly' indicates an anagram (I've seen this in other clues).
'thing'+'lets'+'in'='thingletsin'
'thingletsin' anagrammed gives 'SILENT NIGHT'.
Can you help me to learn more?
(Other definitions for silent night that I've seen before include "Christmas carol - hours of undisturbed sleep?" , "Blood sucking mammals" .)