Eumhun
To aid in understanding the meaning of a character, or to describe it orally to distinguish it from other characters with the same pronunciation, character dictionaries and school textbooks refer to each character with a combination of its sound and a word indicating its meaning. This dual meaning-sound reading of a character is called eumhun (음훈; 音訓; from 音 "sound" + 訓 "meaning," "teaching").
The word or words used to denote the meaning are often—though hardly always—words of native Korean (i.e., non-Chinese) origin, and are sometimes archaic words no longer commonly used.
Read more about this topic: Hanja