Acater – A Ship's Chandler, this is someone who supplies food provisions to a ship
Accipitrary – A Falconer
Accomptant - Accountant
Accoucheur - one who assists women in childbirth, midwife
Ackerman, Acreman - ploughman, ox herder
Actuary - accountant
Affeeror - official in the manorial courts responsible for assessing the monetary penalty and collecting taxes and dues, assessor
Alchemist - medieval chemist who claimed to be able to turn metal into gold
Ale Conner - official who tested the quality and measure of ale served in public houses
Ale-draper, Ale Draper - a tapster, seller of ale
Ale-tunner, Ale Tunner - one who worked among and on "tuns," great hogshead barrels used to store ale in medieval times
Ale-wife, Alewife - landlady of an ale house, or ale stand
All Spice - grocer
Almoner - one who distributes alms, provides for the needy; in Britain may also refer to a hospital social worker
Amanuensis - stenographer, one who takes dictation
Amen Man - parish clerk
Ankle Beater - young person who helped drive cattle to market
Apiarian - beekeeper
Apiculteur - beekeeper (French)
Apparitor - official who summoned witnesses for the ecclesiastical courts
Apothecary - One that prepares and sells drugs and medicines, a pharmacist
Archiator - doctor, physician
Armiger - squire who carried the armor of a knight
Arpenteur - land surveyor (French)
Arrimeur - stevedore, one who is employed in the loading and unloading of ships (French)
Artificer - a skilled craftsman or artisan; an enlisted military man responsible for upkeep of weapons and small arms; or an inventor
Aubergiste - inn keeper (French)
Aurifaber - a goldsmith, or one who works with gold
Provided by http://genealogy.about.com/library/glossary/bl_occupations-a.htm