Sign tourists often lack sense... (6)
I believe the answer is:
intuit
'sense' is the definition.
(I've seen this before)
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for intuit that I've seen before include "Understand by instinct" , "Feel" , "makes sense" , "Instinctively come to know" , "Know by direct perception" .)