Business picking up? (4)
I believe the answer is:
taxi
This could be a double definition.
'business picking' is the first definition.
Although both the answer and definition are singular nouns, I cannot understand how they can define each other.
'up?' is the second definition.
Although both the answer and definition are verbs in their base form, I don't understand how they can define each other.
Can you help me to learn more?
(Other definitions for taxi that I've seen before include "US currency" , "Part of fleet" , "Move along a runway" , "Public service vehicle" , "Rank occupant" .)