第 (dì) — (prefix) used before a number to form ordinal numbers (first, second, third, etc.)

A prefix that turns a number into an ordinal ('first, second, third…'). It is not a number itself and never stands alone — always write 第一, 第二, 第三.

Most characters — around four in five — are built this way: one part hints at the meaning, the other at the pronunciation.

第 shows 𥫗, the bamboo strips once used for writing and sorting, with 弟 giving the sound.