| Oakum-boy | According to The Sailor's Word-Book, published in 1867 by William Henry Smyth, this was a name for "the caulker's apprentice, who attends to bring oakum, pitch, &c." |
| Oastler | A variation in the spelling of the name: ostler. |
| Officer | According to The Sailor's Word-Book, published in 1867 by William Henry Smyth, this was a name for a "person having some command." |
| Officer Of The Day | According to The Sailor's Word-Book, published in 1867 by William Henry Smyth, this was a name for a "military officer whose immediate duty is to attend to the interior economy of the corps to which he belongs, or of those with which he may be doing duty." |
| Officer Of The Watch | According to The Sailor's Word-Book, published in 1867 by William Henry Smyth, this was a name for the "lieutenant or other officer who has charge of, and commands, the watch." |
| Oiler | A manufacturer of, or dealer in, oil; an oilman. Also, one who oils or lubricates with oil. |
| Oilman | A manufacturer or seller of oil. Also, a dealer in sweet oils and eatables preserved in them.. Also, a worker in an oil mill. Also, a man who oils machinery. |
| Olpis | According to The Sailor's Word-Book, published in 1867 by William Henry Smyth, this was a name for "one who, from a shore eminence, watched the course which shoals of fish took, and communicated the result to the fishers." |
| One In Ten | According to the 1811 Dictionary Of The Vulgar Tongue, by Captain Grose, this was a name for a parson. |
| Opholder | A variation in the spelling of the name: upholder. |
| Optician | One skilled in opticks. [UEED] |
| Orderly | According to The Sailor's Word-Book, published in 1867 by William Henry Smyth, this was a name for "the bearer of official messages, and appointed to wait upon superior officers with communications." |
| Orderly Officer | According to The Sailor's Word-Book, published in 1867 by William Henry Smyth, this was a name for the "Officer Of The Day." |
| Ordinary | Applied to a person or staff of persons. Also, a judge having authority to take cognizance of cases in his own right and not by delegation. Also, An officer in a religious fraternity having charge of the convent, etc. The name was also applied to an inn or tavern: in parts of the United States, as Virginia: a tavern or inn of any kind. |
| Ordinary-holder | According to Everett B. Wilson in his book Early America At Work, published in 1963, this was another name for an ordinary-keeper. |
| Ordinary-keeper | According to Everett B. Wilson in his book Early America At Work, published in 1963, this was the name of an inn, or tavern-keeper, if the inn was known by the name of 'ordinary'. |
| Osler | A bird-catcher. |
| Osteler | A variation in the spelling of the name: ostler. |
| Ostelere | A variation in the spelling of the name: ostler. |
| Osteller | A variation in the spelling of the name: ostler. |
| Ostelor | A variation in the spelling of the name: ostler. |
| Ostiary | A doorkeeper, esp. of a church. |
| Ostiler | A variation in the spelling of the name: ostler. |
| Ostler | A man who attends to horses at an inn; a stableman, a groom. A phonetic spelling of Hosteler, Hostler, representing the historical pronounciation with h mute. |
| Ostman | According to The Sailor's Word-Book, published in 1867 by William Henry Smyth, this was another name for an "hoastman." |
| Outcrier | On who sells by auction. |
| Outrider | An officer of the sheriff's court whose duties included collecting dues, delivering summonses, etc. Also, An officer of an abbey or convent, whose duty it was to attend to the external domestic requirements of the community, esp. to look after the manors belonging to it. Also, a forager of an army. A highwayman. Also, a commercial traveller; a tradesman's travelling agent. Also, a mounted attendant who rides in advance of or beside a carriage. In the U.S. the name also applied to: a mounted herdsman who prevents cattle from straying beyond a certain limit. Outriders are bailiffs errant imployed by sheriffs to ride to the farthest places of their counties or hundreds, with the more speed to summon persons into county-courts. [According to A New Law Dictionary, by Giles Jacob, 1744] |
| Overlayer | One who or that which overlays or overlies something. |
| Overseer | One who oversees or superintends, a supervisor; esp. one whose business it is to superintend a piece of work, or a body of workmen; a superintendant (of workmen, slaves, convicts, etc.). |
| Overseer of the Poor | Overseers of the Poor are publick officers created to provide for the poor of every parish. [According to A New Law Dictionary, by Giles Jacob, 1744] |
| Owler | Owlers are persons that carry wool, &c, to the sea-side by night in order to be shipped off contrary to law. [According to A New Law Dictionary, by Giles Jacob, 1744] One engaged in the illegal exportation or 'owling' of wool or sheep from England. |
| Owner | According to The Sailor's Word-Book, published in 1867 by William Henry Smyth, this was a name for a "proprietor in a ship." |
| Ox-boy | A boy who tends oxen; a cowboy. |
| Ox-feller | A butcher. |
| Oxman | A man who looks after oxen; a herdsman. |
