亦即

yìjí

conjunction

Meanings

Míngtiān, yìjí wǔyuè yī rì, shì láodòngjié.

Tomorrow, that is, May 1st, is Labor Day.

Guāngsù, yìjí měi miǎo yuē sānshí wàn gōnglǐ, shì yǔzhòu zhōng zuì kuài de sùdù.

The speed of light — that is, about 300,000 km per second — is the fastest speed in the universe.

Formal/written. In speech and casual writing use 也就是 (yě jiùshì) instead. 亦即 belongs to academic papers, legal documents, and reference works.

memory

亦 (also) + 即 (namely/that is) — a classical doublet. The 亦 was the literary 'also/likewise' (= modern 也), so 亦即 is just the formal cousin of 也就是.

亦 yì

即 jí