Appear like Lent with a sad tear? (9)

I believe the answer is:
alternate
'appear' is the definition.
The definition and answer can be both related to change as well as being verbs in their base form.
Maybe there's a link between them I don't understand?
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for alternate that I've seen before include "go back and forth" , "Flip" , "Happen in turns, rotate" , "Go in turns" , "Happening or following in turns, one after the other" .)
