spineless

(s) weak in willpower, courage or vitality namby-pamby, wishy-washy, gutless,
(a) lacking a backbone or spinal column
- worms are an example of invertebrate animals
invertebrate,
(a) lacking spiny processes
- spineless fins
(s) lacking thorns thornless,

Synonyms

namby-pamby wishy-washy gutless invertebrate thornless

Antonyms

vertebrate spinous spiny

Words of close approximity

spinelessness