Synonyms of inefficient

Adjective

1. inefficient (vs. efficient), uneconomical, wasteful, incompetent, ineffective#1, uneffective#1, ineffectual

usage: not producing desired results; wasteful; "an inefficient campaign against drugs"; "outdated and inefficient design and methods"

2. ineffective, inefficient, incompetent (vs. competent)

usage: lacking the ability or skill to perform effectively; inadequate; "an ineffective administration"; "inefficient workers"

Definition and meaning of inefficient (Dictionary)