What is the antonym of the word 'Neophyte'?

• Neophyte (noun)
English Meaning: Someone who has recently become involved in an activity and is still learning about it.
Bangla Meaning: কোনো ধর্মমতে অধুনাদীক্ষিত ব্যক্তি; নবদীক্ষিত, শিক্ষানবিস।

• Synonyms: Beginner (যে ব্যক্তি এখনো নবিস এবং অনভিজ্ঞ), Novice (শিক্ষানবিশ), Newcomer (আগন্তুক), Apprentice (আনাড়ী), Amature (অপেশাদার)।

• Antonyms: Expert (বিশেষজ্ঞ বা দক্ষ ব্যক্তি), Master (দক্ষ), Professional (পেশাগত), Veteran (অভিজ্ঞ), Maestro (উস্তাদ), Ace (সেরা ব্যক্তি)।

Example Sentence: 
1. The actual English teaching that gets done in this situation may be minimal, while the neophyte teacher is busy struggling for survival.
2. Neophytes are assigned an experienced church member to guide them through their first year.

Source: website Lecture.