A person of authority in the military who has not received a commission (a direct conveyance of authority from the sovereign government); as such they can have charge or control but not command in the most technical use of the word.

plural of persona non grata

(physics) a fluid whose stress at each point is not linearly proportional to the strain rate at that point; i.e. its viscosity depends on the applied shear force

(chemistry) Any chemical compound in which the number of atoms of each element is not expressible as the ratio of small integers; normally due to missing atoms in a solid state lattice.

(role-playing games, video games) A character in a role-playing game or computer game whose actions are not controlled by a player.

Alternative spelling of non-governmental organization

(botany) Any plant that does not have a vascular system

A legally constituted non-commercial organization created by natural or legal persons with no participation or representation of any government.

plural of non-maskable interrupt

Any of various small two-winged flies, belonging to the family Chironomidae in the order Diptera.