dekametre, (kokuji)
籵 is a Japanese-made kokuji that represents the unit dekametre (ten metres). It has no broader conceptual center beyond this specific measurement meaning.
籵 is a kokuji created in Japan by combining 米 (metre) and 十 (ten) to represent the unit dekametre (ten metres).
The left side 米 stands for metre, and the right side 十 means ten. Together they form a dekametre: ten metres.
For デカメートル, think of a deca-metre: the English word 'deca' sounds like デカ, and 'metre' becomes メートル. Picture a ten-metre measuring tape marked with 米 and 十.