Observe and follow (3)
I believe the answer is:
see
I believe this is a double definition.
'observe' is the first definition.
(observe can mean to see something)
'follow' is the second definition.
(both can mean to understand)
'and' is the link.
(Other definitions for see that I've seen before include "Realize" , "Perceive; meet (someone)" , "Visit" , "Perceive mentally" , "View; prelacy" .)