ˈslumberless,a.|ˈslʌmbəlɪs| [f. slumber n. + -less.] Obtaining or yielding no slumber; sleepless. 1820Shelley Prometh. Unb. i. i. 563 The present is spread Like a pillow of thorns for thy slumberless head.1884Cent.Mag. XXIX. 88 The overstraining and almost slumberless labor of the last days and nights.