a person with good judgement on matters in which knowledge or artistic taste is needed

authority

a person who gives expert advice (e.g. in medicine, business)

professional advisor

a skilled workman who practices a craft

skilled person

a person who has been trained in medical science

medical practitioner

draughts-man

skilled person

a kind of small brightly-coloured bird that feeds on fish

expert, animate or inanimate

a doctor of medicine and surgery

person trained in medical science

a professional person, especially in medicine or law

expert

the starting point (of a river); a place or person from which something comes or is got; original documents etc for an academic study

beginning; point of supply

a doctor who performs medical operations

person trained in medical science