単独
たんどく · tandoku · JLPT N1 · na-adj
single
独 — dog radical 犭 + 蜀 (phonetic)
A semantic-phonetic compound: 犭 (dog) gives the meaning, since dogs were thought to fight when kept together and so were often kept singly, while 蜀 supplies the sound. The original sense was 'solitary dog,' which broadened to 'alone, single, only.'