Noel goes astray in darkness, lacking this? (4,5)
I believe the answer is:
neon light
'lacking this?' is the definition.
I know nothing about this answer so I can't judge whether this works.
'noel goes astray in darkness' is the wordplay.
'goes astray' indicates anagramming the letters.
'in' is an insertion indicator.
'darkness' becomes 'night' (night is a period of darkness).
'noel' anagrammed gives 'eonl'.
'eonl' going within 'night' is 'NEON LIGHT'.
Can you help me to learn more?
(Other definitions for neon light that I've seen before include "What may shine" , "Illumination used for advertising" , "Type of illumination" , "Source of illumination" , "Type of fluorescent lamp" .)