Adjective

(en adjective)

Not efficient; not producing the effect intended or desired; inefficacious; as, inefficient means or measures.

Celery is an inefficient food.

Incapable of, or indisposed to, effective action; habitually slack or remiss; effecting little or nothing; as, inefficient workers; an inefficient administrator.

Jessica was terribly inefficient at cleaning, so her brother usually had to clean the whole room.

Adjective

(en adjective)

Useless; unproductive.

The unskilled man's attempt at fixing his car engine was fruitless .

{{quote-Fanny Hill, part=2 , At length, after repeated fruitless trials, he lay down panting by me, kiss'd my falling tears, and asked me tenderly what was the meaning of so much complaining? }}

Bearing no fruit; barren.

The fruitless woman desperately wanted to have children.

(rare) Without fruit.

* 1923 , The Homestead (issues 386-410, page 33)

The first fruits of the season were eagerly sought after, and everybody was thankful that once more dread winter with its unvarying monotony of fruitless meals was a thing of the past.

* 1966 , Joseph Irving Goodman, Diet and live (page 14)

the many individual claims as to the ideal diet , for instance, the high-carbohydrate diet, the milkless diet, the breadless diet, the meatless diet, the fruit diet or the fruitless diet, the high-protein or the low-protein diet, and innumerable variations.