No Vacancy, Jam-Packed
noun, の adjective
Full of members, so sorry, no more room. This place is a full house. That means there is no vacancy here.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
I hate that I have to stand in a jam-packed train until I arrive at Shinjuku station every morning.