provisions
粻 centers on stored food supplies: provisions, especially grain-based ones, kept for future use.
粻 combines 米 (rice/grain) with 長, which likely contributes the sound and may suggest long-lasting or extended storage of grain provisions.
Rice 米 stored for a long 長 time becomes provisions: 粻 is grain kept as food supplies.
For チョウ, imagine a long-serving chief named Chou inspecting the grain provisions: Chou -> チョウ, and the rice 米 is stored for the long 長 haul.