The suffix -ician is best linked to the medical doctor
Practitioner
Define ordinary expert?
An expert or specialist in psychology.
BORED
expert opinions about matter and energy
An orthopedic doctor/surgeon.
Expert testimony is defined as testimony from an expert in the field. For example, if a doctor testified at the court, he would be an expert testimony in the court.
a person who has special skill or knowledge in some particular field
Consultant, clinic, expert, practitioner, specialist.
i am no expert but i could say to go to the hospital or a local Doctor.
'Expertive' is not a word in English. 'Expert' means someone who is very proficient at something.
Ask a doctor