Expertise and Mastery Are NOT the Same...

expert
/ noun, verb ek-spurt; adjective ek-spurt /

DEFINITION:

noun
1 a person who has special skill or knowledge in some particular field; specialist; authority:
a language expert.
2 Military.
a- the highest rating in rifle marksmanship, above that of a marksman and sharpshooter.
b- a person who has achieved such a rating.

adjective
3 possessing special skill or knowledge; trained by practice; skillful or skilled (often followed by "in" or "at"):
an expert driver; an expert in driving; to be expert at driving a car.
4 pertaining to, coming from, or characteristic of an expert:
expert work; expert advice.