noun
Archaic term for a double suicide, typically of lovers. Modern Japanese usually uses 心中 (しんじゅう).
江戸時代の浄瑠璃には、相対死の場面がよく描かれる。
Scenes of double suicide are often depicted in Edo-period jōruri plays.
The modern standard term for double suicide, especially lovers' suicide. 相対死 is its archaic predecessor.
Compound of 相対 (aitai, 'facing each other; mutual') and 死 (shi, 'death'), with the nominalizing suffix に (ni). The exact historical derivation is uncertain, but it refers to a mutual death pact.