spineless (adj.)
- abulic
- adrift
- afloat
- afraid
- alternating
- amorphous
- anemic
- asthenic
- bloodless
- capricious
- changeable
- changeful
- chicken
- cowardly
- craven
- dastardly
- debilitated
- desultory
- dizzy
- drooping
- droopy
- dull
- eccentric
- effete
- emasculate
- erratic
- etiolated
- faint
- fainthearted
- fearful
- feeble
- feebleminded
- fickle
- fitful
- flabby
- flaccid
- flickering
- flighty
- floppy
- fluctuating
- forceless
- frail
- freakish
- giddy
- gone
- gutless
- imbecile
- impetuous
- impotent
- impulsive
- inadequate
- inconsistent
- inconstant
- indecisive
- ineffective
- ineffectual
- infirm
- invertebrate
- irregular
- irresolute
- irresponsible
- languid
- languorous
- lily-livered
- limber
- limp
- listless
- mazy
- mercurial
- moody
- nerveless
- pliable
- powerless
- pusillanimous
- rambling
- restless
- roving
- rubbery
- sapless
- scatterbrained
- shapeless
- shifting
- shifty
- slack
- soft
- spasmodic
- spiritless
- squeamish
- timid
- timorous
- unaccountable
- uncertain
- uncontrolled
- undependable
- undisciplined
- unfixed
- unhardened
- unnerved
- unpredictable
- unreliable
- unrestrained
- unsettled
- unstable
- unsteady
- unstrung
- vacillating
- vagrant
- variable
- volatile
- wandering
- wanton
- wavering
- wavy
- wayward
- weak
- weak-kneed
- weakly
- whimsical
- white-livered
- wishy-washy
- yellow
