Finish an "i" (3)
I believe the answer is:
dot
'finish an i' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for dot that I've seen before include "Full stop, period or tittle" , "Spot, speck" , "Little girl" , "One signal used in Morse code" , "Long-ago year?" .)