Arrive on locomotive's caboose? (4)
I believe the answer is:
lobe
'caboose?' is the definition.
Although both the answer and definition are singular nouns, I cannot understand how one could define the other.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lobe that I've seen before include "Roundish projecting part" , "Rounded projection of a larger structure" , "Base of ear" , "flap" , "Lower part of the ear" .)