Lead-in to boarding (3)
I believe the answer is:
pre
(Other definitions for pre that I've seen before include "Before starting" , "Combining form meaning before" , "Prefix meaning before" , "Before or ahead of" , "Before, prior to" .)
I believe the answer is:
pre
(Other definitions for pre that I've seen before include "Before starting" , "Combining form meaning before" , "Prefix meaning before" , "Before or ahead of" , "Before, prior to" .)