expert

/ˈɛkspərt/
noun
  1. A person who has a high level of knowledge or skill in a particular subject.
    • The police called in a bomb disposal expert to handle the situation.
    • She is an expert in ancient Roman history.
    • My dad is an expert at fixing old cars.
adjective
  1. Having or showing great knowledge or skill in a particular area.
    • He gave expert advice on how to invest money wisely.
    • The chef's expert knife skills impressed everyone watching.
    • She is an expert gardener who can grow almost anything.