Synonyms of 'veteran'
old handDictionary, master, pro (informal)
Graf was already a tennis veteran at the age of 21.
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If you say that someone is a master of a particular activity, you mean that they are extremely skilled at it.
He is a master at blocking progress.
If someone is an old hand at something, they are very skilled at it because they have been doing it for a long time.
He is an old hand at organizing training courses.
Thesaurus for veteran from the Collins English Thesaurus
A veteran is someone who has served in the armed forces of their country, especially during a war.