Pro se

Pro se is a Latin adjective meaning "for self", that is applied to someone who represents himself or herself without a lawyer in a court proceeding, whether as a defendant or a plaintiff and whether the matter is civil or criminal. This status is sometimes known as "propria persona" or "pro per". In England and Wales the phrase "Litigant in Person" is used.
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Latin: in one’s personal behalf. Contrast with pro socio. - (read more on Pro se)
  

used to designate an independent inventor who has elected to file an application by themselves without the services of a licensed representative.

Context: Patent 

Lat. "for himself" "on one's own behalf" A person who represents himself in court

alone without the help of a lawyer is said to appear pro se. (2) Lat. for “you lose.” also pro per

On one's own behalf