Merriam-Webster's Collegiate® Dictionary, 11th Edition
CHARTER
I. noun
Etymology: Middle English chartre, from Anglo-French, from Medieval Latin chartula, from Latin, diminutive of charta
Date: 13th century
a written instrument or contract (as a deed) executed in due form,
2. a grant or guarantee of rights, franchises, or privileges from the sovereign power of a state or country, a written instrument that creates and defines the franchises of a city, educational institution, or corporation, constitution , a written instrument from the authorities of a society creating a lodge or branch, a special privilege, immunity, or exemption, a mercantile lease of a ship or some principal part of it, a charter travel arrangement,
II. transitive verb
Date: 15th century
1. to establish, enable, or convey by charter, certify , to hire, rent, or lease for usually exclusive and temporary use , see: hire charterer noun
III. adjective
Date: 1922
of, relating to, or being a travel arrangement in which transportation (as a bus or plane) is hired by and for one specific group of people