1. (adjective) producing or capable of producing an intended result or having a striking effect

• effective
• efficacious

2. (adjective) having legal efficacy or force

• legal
• sound

1. (adjective) producing or capable of producing an intended result or having a striking effect

• efficacious
• efficient
• potent
• stiff
• strong
• powerful
• useful
• utile

1. (adjective) producing or capable of producing an intended result or having a striking effect

• hard-hitting
• trenchant
• impelling
• impressive
• telling
• rough-and-ready

2. (adjective) having legal efficacy or force

• valid

1. (adjective) producing or capable of producing an intended result or having a striking effect

• effect
• effectuate
• set up
• effectiveness
• effectiveness
• effectiveness
• effectiveness
• effectivity
• effectivity
• effectivity
• effectivity
• effectuality
• effectuality
• effectuality
• effectuality
• effectualness
• effectualness
• effectualness
• effectualness
• efficaciousness
• efficaciousness
• efficacy
• efficacy

2. (adjective) having legal efficacy or force

• legality

1. (adjective) producing or capable of producing an intended result or having a striking effect

• ineffective
• ineffectual
• uneffective