Double pleat (4)
I believe the answer is:
fold
I believe this is a double definition.
'double' is the first definition.
(thesaurus)
'pleat' is the second definition.
(I know that pleat is a more specific form of fold)
(Other definitions for fold that I've seen before include "Tuck - pen" , "Members of church" , "Prepare pages to put in small envelope" , "stop functioning" , "Gather < church" .)