say it: SPAHYN-luhs
spineless is an adjective meaning "weak in willpower, courage or vitality". It carries 4 recorded senses.
weak in willpower, courage or vitality
lacking a backbone or spinal column
“worms are an example of invertebrate animals”
zoology
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for spineless come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.