Follows stealthily (6)
I believe the answer is:
stalks
'follows stealthily' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for stalks that I've seen before include "They support plants" , "Pursues stealthily, game or person" , "Main stems of plants" , "'Stems, plant supports (6)'" , "Follows stealthily with evil intent" .)