及

It is used for ideas like affecting or influencing something, reaching or extending to a point, or arriving somewhere.

Important note: It does not mean “to go insane.”

For the meaning “to go mad,” the character 狂(광) is used.

及 is a compound ideogram made from:

人 (인) – “person”

又 (우) – “hand/again”

It visually suggests a person reaching out with the hand, conveying the meaning “to reach, to extend.”

In Korean, 及 also carries the adverbial meaning of “및” (and), similar to and in English.

In Classical Chinese and Modern Chinese literary usage, 及 is frequently used in this “and” sense.

In Japanese, the conjunction 及び (oyobi) comes from the continuative (noun) form of the verb 及ぶ (およぶ, oyobu), meaning “to reach” — and is also used to mean “and.”

The upper part of 急 (급, “urgent”), called 刍, is derived from a modified form of 及 — showing how 及 has served as a base component in later characters.