The use of two or more synonyms or near-synonyms in legal English where one term would be adequate.  There is a curious historical tendency in legal English to string together two or three words to convey what is usually a single legal concept.

Couplets/doublets (parings of synonyms; two similar things; a pair)
acquire and gain property
bring and file suit
cease and desist from doing
fit and proper, perform and discharge,
free and clear
goods and chattels
indemnify and hold harmless from any and all liability
null and void
private and confidential
showed no remorse or contrition
terms and conditions
waive and relinquish any and all right or claim
without let or hindrance

Triplets (A group or set of three of one kind.)
dispute, controversy or claim
give, devise and bequeath
Hereof, Thereof, and Everywhereof
promise, agree and covenant.
rest, residue and remainder

Plain-English advocates suggest that no document can possibly cover every contingency, and that lawyers should not attempt to encompass every contingency they can foresee. Rather, lawyers should only draft for the known, possible, reasonably expected contingencies.

a) Binômios
- each and every
- any and all
- due and payable
- by and between
b) Trinômios
- authorized, executed and delivered
- legal, valid and binding
- illegal, invalid or unenforceable
- full, true and correct
- right, title and interest
c) Sequência de termos [Polinômios]
- demand, presentment, protest and other notice
- legality, validity, binding effect or enforceability

Diferentemente do passado, a tendência, hoje, é a de evitar o emprego de termos supérfluos. Garner (2001), entre outros autores, recomenda que o uso de binômios e trinômios seja evitado na linguagem jurídica que, em inglês, é historicamente redundante. O autor recomenda ainda a aplicação de duas regras – que a meu ver também poderiam ser aplicadas à tradução dos termos objeto da questão da leitora quando empregados em polinômios – a saber:
- se uma palavra abrange o sentido de outras, usar só aquela (e.g. full, true and correct)
- se as palavras são sinônimas (e.g. legal, valid and binding), usar a que couber melhor no contexto.