The most common and most likely answer to this crossword clue is the 7 plus 7 letter word CHINESE LANTERN
I've seen this crossword clue in The Guardian
C
H
I
N
E
S
E
L
A
N
T
E
R
N
More clues leading to the result CHINESE LANTERN
- Product perhaps unique to Asian light industry?
- It grows light from the East
- Central sheen in exotic light source
- . . . . search line ten round about bottom of down light
- It grows light in the East
- With which some Asians cover bulb for garden plant
- For a race both sides accept a bet — pole position will throw some light
Buddy explains!
The straight part
We know that "light source" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case light source = chinese lantern.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.