You can say "Oh, come on, how could legal terms have synonyms and antonyms? Tell me then a synonym for the term ”foreclosure”, or an antonym for the term ”fee simple absolute”. And you have a point there. Yet, there exist synonyms also in law. True, synonyms as they are, they are not interchangeable.
Let's take the example of effect, in particular commencement of effect:
>When it is a person commencing the effect of a contract, s/he enters into it/brings/carries it into force/effect. When it is a state, it codifies/enacts/passes/promulgates, ratifies the instrument, when it is a court, it returns/passes a final/conclusive order/judgment. Instruments take effect/come /enter into effect/force, become effective/applicable/enforceable.
And what are the antonyms of the above terms?
>When it is a person discontinuing the effect of an instrument, s/he cancels/nullifies/rescinds/terminates it. When it is a state, it abrogates/annuls/repeals/suspends it, when it is a court, it overturns/sets aside/vacates a judgment. When it is a writ, it abates. Instruments expire/discontinue/lapse/terminate.
It is simply a must to know these terms. All of them. Like a native pro.
The concept of effect, force and applicability is described in the book entitled 'A Practical Guide to English for Law' in a total of 18 pages. It is also described in PDF ebook entitled 'Terminology of Contract Law in Use'.