anode

In a battery or electrolysis, a reaction occurs at one electrode that releases electrons, and a reaction occurs at the other electrode that receives electrons. For example, in the electrolysis of water,

The former is called an anodic reaction, and the electrode where this reaction occurs is called the anode. The latter reaction is called a cathodic reaction, and the electrode is called the cathode. In a battery, the anode is the negative electrode and the cathode is the positive electrode, but in the case of electrolysis, the opposite is true, which can easily lead to confusion. For this reason, it is not advisable to refer to the electrodes by terms other than anode and cathode that are linked to yin and yang, or positive and negative.

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

電池あるいは電解操作では，一方の電極では電子を放出する反応が，他方の電極では電子を受けとる反応が起こっている．たとえば，水の電解では，

となり，前者をアノード反応(anodic reaction)といい，この反応の起こっている電極をアノードとよぶ．また，後者の反応をカソード反応(cathodic reaction)といい，電極をカソードという．電池の場合はアノードは陰極，カソードが陽極となり，電解の場合はこの逆となるので，混乱をまねきやすい．したがって，電極をアノード，カソード以外の陰陽，正負に結びついた表現でよぶのは好ましくない．

出典　森北出版「化学辞典（第2版）」化学辞典 第2版について　情報