simple past tense and past participle of pack
"The train was packed full of passengers waiting to leave the station."
In plain English: To pack something means to fill it tightly with items so there is very little empty space left inside.
"The stadium was packed with fans for the big game."
extremely crowed or filled to capacity
"a suitcase jammed with dirty clothes"
"stands jam-packed with fans"
"a packed theater"
Put into a package.
"The factory workers packed the newly manufactured toys into cardboard boxes before shipping them out."