Guided by a small light (3)
I believe the answer is:
led
I believe this is a double definition.
'guided' is the first definition.
('lead' can be a synonym of 'guide')
'a small light' is the second definition.
(light emitting diode)
'by' is the link.
(Other definitions for led that I've seen before include "associated with Zeppelin" , "induced to" , "Conducted" , "Went at the head of others" , "showed the way ahead" .)