This is a double definition - the clue contains two separate definitions that both lead to the same answer word.
Look for two different meanings of the same 4-letter word. One meaning relates to 'spike' (as in adding something to a drink), and the other meaning relates to 'netting' (a type of delicate fabric material).
Answer: LACE | This has two definitions: to 'lace' means to spike (as in lacing a drink with alcohol or drugs), and 'lace' is also a type of delicate netting fabric.