Ineffectual (adjective)

1. Not having a strong or noticeable effect; failing to produce the desired outcome.
2. Lacking the ability or power to produce a desired result or effect.

Origin:

Late 17th century: from french inefficace or latin inefficax, from in- 'not' + efficax, efficac- 'effective'.

Examples:

1. The ineffectual solution was unable to solve the problem.
2. The ineffectual attempts to revive the dying company were futile.
3. The ineffectual leader was unable to inspire or motivate the team.
4. The ineffectual product was quickly forgotten and replaced by a better one.
5. The ineffectual response to the crisis was criticized for being too slow and insufficient.