The flat stones shone weirdly (5)
I believe the answer is:
hones
'the flat stones' is the definition.
'hones' can be an answer for 'stones' (hone is a kind of stone). I'm not certain of the 'the flat' bit.
'shone weirdly' is the wordplay.
'weirdly' is an anagram indicator.
'shone' anagrammed gives 'HONES'.
Can you help me to learn more?
(Other definitions for hones that I've seen before include "Sharpens, like knife on stone" , "Perfects, sharpens" , "Sharpens as on whetstone" , "gets sharp" , "Sharpens on strap, say razor" .)