A flower to you, a small reptile to us (6)
I believe the answer is:
crocus
'a flower' is the definition.
(I've seen this before)
'reptile to us' is the wordplay.
'reptile' becomes 'croc' (I've seen this before).
'croc'+'us'='CROCUS'
'to you a small' acts as a link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for crocus that I've seen before include "Yellow, purple or white spring flower" , "Slow transition" , "Plant from a corm" , "Occurs (anag.)" , "Spring plant" .)