Five cheer in Mexico for little rodent (4)
I believe the answer is:
vole
'rodent' is the definition.
(I know that vole is a type of wood rat)
'five cheer' is the wordplay.
'five' becomes 'V' (Roman numeral).
'cheer' becomes 'ole' (I've seen this in another clue).
'v'+'ole'='VOLE'
'in mexico for little' is the link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for vole that I've seen before include "River-bank rodent" , "Small mouse-like rodent" , "creature" , "Small mammal - one to love" , "Small burrowing animal - love it" .)