Second place, not first, to find ruminant (5)
I believe the answer is:
moose
'ruminant' is the definition.
(moose is a kind of ruminant)
'second place not first to' is the wordplay.
'second' becomes 'moo' (I can't justify this - if you can you should believe this answer much more).
'place' becomes 'set' (synonyms).
'not' suggests deleting specific letters.
'first to' becomes 't' (mst letter of 'to').
'set' with 't' taken out is 'se'.
'moo'+'se'='MOOSE'
'find' acts as a link.
Can you help me to learn more?
(Other definitions for moose that I've seen before include "Large northern deer" , "North American deer" , "Animal" , "Large N American deer like European elk" , "North American elk" .)