The title, "Logorrhea," means an uncontrollable flood of words, and the poem puts the reader inside a sleepless night where the speaker's mind won't stop talking. Instead of resting, it chatters on like a drunk, rambling and repeating, and the speaker can't break free of it.
The last two stanzas turn the idea into a small, strange picture. The "plainest words in the world" collect under the bed, as if they were dust, lost shoes, or something half-hidden that comes out in the dark. The speaker searches for one word that is truly their own, something simple and honest, and can't find it. Their eyes ache from the effort.
The feeling is exhausted and frustrated. There is a quiet irony too: a mind overflowing with language still can't produce the one word it needs. The mood is tired, restless, and a little darkly funny, the way sleepless nights can be.