The most common and most likely answer to this crossword clue is the 7 letter word LEMMING
I've seen this crossword clue in The Times
L
E
M
M
I
N
G
More clues leading to the result LEMMING
Buddy explains!
The straight part
We know that "rodent" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case rodent = lemming.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.
What does LEMMING mean?
LEMMING noun- A small Arctic and Subarctic rodent from any of six genera of similar rodents.
- Any member of a group given to conformity or groupthink, especially a group poised to follow a leader off a cliff.