ineffective

/ɪnəˈfɛkɾɪv/

/ɪnɛˈfɛktɪv/

Use the adjective ineffective to describe something that doesn't work quite the way it's supposed to. You might complain about your ineffective guard dog, who wags his tail and licks everyone who comes to your house.

When you're ineffective, you're unable to accomplish something you're trying to do. You might realize that you're an ineffective babysitter when you can't get the kids to go to bed. Ineffective comes from the Latin prefix in, "not, or opposite of," added to effective, whose Latin root is effectivus, "productive." When something's unproductive, inefficient, or incapable, it's ineffective.

Definitions of ineffective

1. adjective

   not producing an intended effect
   “an ineffective teacher”

   “ineffective legislation”

   synonyms: ineffectual, uneffective

   idle

   not in action or at work

   toothless

   lacking necessary force for effectiveness

   unproductive

   not producing desired results

   inefficacious

   lacking the power to produce a desired effect

   inefficient

   not producing desired results; wasteful

   powerless

   lacking power

   useless

   having no beneficial use or incapable of functioning usefully

   antonyms:

   effective

   producing or capable of producing an intended result or having a striking effect

   hard-hitting, trenchant

   characterized by or full of force and vigor

   impelling

   markedly effective as if by emotional pressure

   impressive, telling

   producing a strong effect

   rough-and-ready

   crude but effective for the purpose at hand

   efficacious

   marked by qualities giving the power to produce an intended effect

   efficient

   being effective without wasting time or effort or expense

   potent, stiff, strong

   having a strong physiological or chemical effect

   impactful, powerful

   having great power or force or potency or effect

   useful, utile

   being of use or service
2. adjective

   lacking in power or forcefulness
   synonyms: ineffectual, unable

   impotent

   lacking power or ability
3. adjective

   lacking the ability or skill to perform effectively; inadequate
   “an ineffective administration”

   synonyms: inefficient

   incompetent

   not qualified or suited for a purpose