1) Brimful 2) Brimming with 3) Busy 4) Chock-full 5) Congested 6) Crammed 7) Crammed full 8) Crowded 9) Filled to capacity 10) Full 11) Heaving 12) Jam-packed 13) Jam-pawncked 14) Jammed 15) Like an SRO theater 16) Like sold-out theaters 17) Overflowing 18) Packed like sardines 19) Packed out 20) Packed to the gunwales Found on https://www.crosswordclues.com/clue/packed
Refers to measuring brown sugars. Spoon brown sugar nto dry measuring cup and press down until firmly packed, overfilling slightly, then leveling. When dumped out, should hold its shape (as when making sand castles). Found on https://www.homebaking.org/glossary/