1) French word used in English 2) One putting in an application 3) Petitioner 4) Suppliant 5) Supplicant 1) Petitioner 
A postulant (from postulare, to ask) was originally one who makes a request or demand; hence, a candidate. The use of the term is now generally restricted to those asking for admission into a monastery or a religious institute, both before actual admission and for the period of time preceding their admission into the novitiate. Currently, however,...
candidate for a religious order
• (n.) One who makes a request or demand; hence, a candidate.
Pos'tu·lant noun [ French, from Latin postulans , present participle of postulare . See Postulate .] One who makes a request or demand; hence, a candidate. 
[n] - one submitting a request or application especially one seeking admission into a religious order
noun one submitting a request or application especially one seeking admission into a religious order