spineless

adjectives

weak in willpower, courage or vitality
gutless, namby-pamby, spineless, wishy-washy
is derived from
spinelessness
lacking a backbone or spinal column
"worms are an example of invertebrate animals"
invertebrate, spineless
lacking spiny processes
"spineless fins"
spineless
antonym
spinous
lacking thorns
spineless, thornless