SPINELESS definition: 1. A spineless person does not have much determination and is not willing to take risks: 2. A…. Learn more. The meaning of SPINELESS is free from spines, thorns, or prickles. How to use spineless in a sentence. SPINELESS meaning: 1 : lacking courage or strength; 2 : having no spine or spines Definition of spineless adjective in Oxford Advanced Learner's Dictionary. Meaning, pronunciation, picture, example sentences, grammar, usage notes, synonyms and more. Define spineless. spineless synonyms, spineless pronunciation, spineless translation, English dictionary definition of spineless. adj. 1. Lacking courage or willpower. · Adjective spineless (comparative more spineless, superlative most spineless) (not comparable) Having no spines, prickles, or thorns. Synonyms: unspined, unspiny Antonyms: spined, … In the case of the president that is being called spineless and middling by the blood-thirsty and his supporters alike, the real or perceived truth hurts particularly when I leaned toward believing that … SPINELESS definition: having no spines or quills. See examples of spineless used in a sentence. If you say that someone is spineless, you mean that they are afraid to take action or oppose people when they should. spineless - WordReference English dictionary, questions, discussion and forums. All Free.