Original: A resident physician or resident ( also called a house officer \/O/ senior house officer in the United Kingdom and several Commonwealth countries ) is a person who has received a medical degree ( MD , DO , MBBS , MBChB ) and who practices medicine under the supervision of fully licensed physicians , usually in a hospital or clinic .
Simplified: A resident physician or resident ( also called a registrar in the United Kingdom ) is a person who has gotten a medical degree and who practices medicine under supervision of other physicians , usually in a hospital .