My article examines Jacques Derrida's readings of Paul Celan's poetry. I take the concept of "idiom" as my initial analytical tool. I understand this concept as the singular's ability to mark language up. In the first part, I put the concept of the "idiom's drive" (pulsion de l'idiome) under closer examination. I refer to Derrida's use of this concept in his Monolinguism of the Other and his reading about Celan's signature in the German language. I subsequently examine the relationship between idiom and mourning as witnessed by the dates found in Schibboleth and Rams. I finally examine the two sessions Derrida devoted to reading Celan's Meridian in the seminar The Beast and the Sovereign, when Derrida deepened his grasp of "counterword" (Gegen-Wort) as conveying a counter-violence against sovereign discourse.