late 14c., "one to whom special duty is entrusted by a higher power," from Medieval Latin commissarius, from Latin commissus "entrusted," past participle of committere (see commit).
Originally especially ecclesiastical, "one who performs a bishop's duties in distant places or when he is absent;" the military sense of "official in charge of supply of food, stores, and transport" dates to late 15c. Hence "storeroom" (1882, U.S. military), especially for selling articles to persons engaged in a particular line of work, and then "dining room in a larger facility" (1924, American English), such as a movie studio.
in a Russian context, "representative appointed by a soviet and responsible for political indoctrination," 1918, from Russian komissar, from German Kommissar "commissioner," from French commissaire, ultimately from Medieval Latin commissarius (see commissary). Earlier in English it meant "commissary" (1640s), from the French word, which itself was used in English from 1753.
c. 1600, in Scottish law, "commissary court," from French commissariat, from Medieval Latin *commissariatus, from commissarius (see commissary). Military sense of "part of an army that supplies transport, provisions, camp equipment, etc.," is from 1779. In reference to the USSR, "ministry," from 1918 (see commissar).
late 13c., "a step in walking," also "rate of motion; the space traveled by the foot in one completed movement in walking," from Old French pas "a step, pace, trace," and directly from Latin passus, passum "a step, pace, stride," noun use of past participle of pandere "to stretch (the leg), spread out," probably from PIE *pat-no-, nasalized variant form of root *pete- "to spread."
It also was, from late 14c., a lineal measurement of vague and variable extent, representing the space naturally traversed by the adult human foot in walking. In some places and situations it was reckoned as the distance from the place where either foot is taken up, in walking, to that where the same foot is set down again (a great pace), usually 5 feet or a little less. The pace of a single step (military pace) is about 2.5 feet.
To keep pace (with) "maintain the same speed, advance at an equal rate" is from 1580s. Pace-setter "one who establishes trends in fashion," is by 1895; it also had literal meanings.
It is customary for the contractor to employ some expert as a pace setter. A man who can thin an acre of beets a day commands as high as $2.00 per day as a pace setter. The other employees are paid in the proportion their work bears to that of the pace setter. The weak, lazy and unskillful get the smallest wage. Besides that the contractor runs a commissary department and feeds the gang. They sleep in tents or in the shade of trees near where they work. [report on Oxnard, Calif., beet harvesting in "The Louisiana Planter and Sugar Manufacturer," May 13, 1899]