ichidan verb
finish telling; tell all
Implies completing the act of telling or narrating something, often with a sense of thoroughness. The verb is a compound of 語る (to tell) and the auxiliary しめる (causative/perfective), giving a nuance of 'make it told' or 'get it told'.
彼はついに真実を語らしめた。
He finally finished telling the truth.
その作家は自伝で半生を語らしめ
The author told the story of half his life in his autobiography.