effectual

adjective

1 effectual political action:

effective, successful, efficacious, productive, constructive, fruitful, potent, powerful;

worthwhile, helpful, of help, of assistance, beneficial, advantageous, valuable, useful, of use.

▷antonyms ineffectual.

2 Lawan effectual document:

valid, authentic, legally acceptable, proper, bona fide, genuine, official, signed and sealed;

lawful, legal, licit, legitimate, (legally) binding, contractual;

in force, in effect, effective.

effectual Oxford Dictionary of English