invertebrate (n.)
- amphibian
- aquatic
- baby
- biped
- canine
- cannibal
- carnivore
- chicken
- cosmopolite
- coward
- crustacean
- crybaby
- doormat
- faint
- feline
- frail
- funk
- gnawer
- herbivore
- insectivore
- jellyfish
- lightweight
- mammal
- mammalian
- marsupial
- milksop
- mollycoddle
- mouse
- namby-pamby
- nebbish
- nonentity
- omnivore
- pansy
- pantywaist
- primate
- protozoan
- pushover
- quadruped
- reptile
- rodent
- ruminant
- scavenger
- sissy
- softy
- sop
- ungulate
- varmint
- vermin
- vertebrate
- weak
- weakling
invertebrate (adj.)
- abulic
- afraid
- amphibian
- aquatic
- biped
- canine
- chicken
- cowardly
- crustacean
- crustaceous
- disorganized
- emasculate
- faint
- fainthearted
- feeble
- feebleminded
- feline
- forceless
- frail
- impotent
- inadequate
- ineffective
- ineffectual
- infirm
- lightweight
- mammalian
- marsupial
- namby-pamby
- pliable
- protozoan
- protozoic
- quadruped
- ruminant
- sissy
- spineless
- ungulate
- vertebrate
- weak
- weak-kneed
