Is “versus” a Spanish word?

Question

RAE says no, wordreference says yes. Is it used or understood by the Spanish speakers?

Answer 1

It isn't Spanish, it's Latin. It is used in Spanish with the same meaning as in English.

See: http://buscon.rae.es/dpdI/SrvltConsulta?lema=versus

Answer 2

No, versus is not a Spanish word. It comes from Latin, but the deal here is that it was first widely used in English for legal documents during the XV century.

It is not very clear but this word could be considered an anglicism since it was first used in English and then in Spanish. Since it may be confusing in regard with its origin and its usage as confrontation and not necessarily as a contrary or opposition of, the RAE recommends using contra or frente a instead.

Source:

versus. Esta preposición, que en latín significaba ‘hacia’, adquirió en el lenguaje jurídico inglés, ya en el siglo xv, el valor de ‘contra’, y con este sentido se usa frecuentemente en el español de hoy: «Kaspárov ‘versus’ Deep Blue: ¿quién ganará la partida?» (País [Esp.] 21.5.97); «Odiosas dicotomías: habla popular versus lengua de cultura, lenguas primitivas versus lenguas avanzadas» (Ninyoles Idiomas [Esp. 1977]). Aparece a menudo en la forma abreviada vs.: «Para hoy se prevé igualmente la confirmación de los escenarios de los partidos Colegiales vs. Olimpia y San Lorenzo vs. Guaraní» (Abc [Par.] 7.11.00). Aunque no es censurable su empleo —pues palabras españolas como adversario, procedentes en latín de la misma raíz que versus, presentan el rasgo semántico de confrontación—, se recomienda sustituir este latinismo anglicado por la preposición española contra o por la locución preposicional frente a.

Translation:

versus. This preposition, that in Latin means 'toward', acquired in the legal language of English, already in the XV century, the meaning of 'against', and with this meaning it is frequently used in the Spanish of today: "Kaspárov, 'versus' Deep Blue: Who will win the match?" ... It is frequently seen in its abbreviated form 'vs' ... Even though it is not a unique usage word - as Spanish words like adversario that come from the same Latin root of 'versus', present an additional meaning of confrontation-, it is recommended to substitute this anglicised latinism for the Spanish preposition of contra or for the prepositional locution frente a.