1. lacking courage or determination; weak-willed
Usage: informal
2. having no spine or backbone
Usage: biology

Examples

• The spinless politician refused to take a stand on the controversial issue.
• He was too spinless to confront his boss about the unfair treatment.
• Jellyfish are spinless creatures that drift through the ocean.
• The spinless invertebrates were studied in biology class.
• She called him spinless for backing down from the challenge.
• Many spinless animals have developed other protective mechanisms.