An Etymological Dictionary of Astronomy and Astrophysics

1. (adj.) Of or pertaining to a single or specific person, thing, group, class, occasion, etc., rather than to others or all; special rather than → general.
   

2a) (n.) An individual or distinct part, as an item of a list or enumeration.

2b) (n.) Logic: An individual or a specific group within a general class (Dictionary.com).

Etymology (EN): M.E., from O.Fr. particuler and directly from L.L. particularis “of a part, concerning a small part,” from L. particula, → particle, + -ar, → -al.

Etymology (PE): Pâruli, adj. from pârul, → particle; pârulé, from pârul + nuance adj. -é.