noun
acrostic poetry; acrostic
A form of Japanese wordplay where the first (or sometimes last) syllable of each line spells out a hidden word or phrase. Often used in waka and other traditional poetry.
折り句は和歌の技巧の一つで、各句の頭文字を読むと別の言葉が現れます。
Acrostic poetry is a technique in waka where reading the first character of each line reveals a hidden word.
The English loanword アクロスティック is sometimes used for Western-style acrostics, while 折り句 specifically refers to the traditional Japanese poetic technique.
From 折り (ori, 'fold' or 'break') + 句 (ku, 'phrase' or 'verse'), referring to the way the hidden message is 'folded' into the lines of the poem.