nonpareil

mastery
UK /nɒnpəˈɹeɪ(l)/ US /ˌnɑnpəˈɹɛl/nounadj

card 1 of 7 · context meaning

What is the meaning of 'nonpareil' in this sentence?

King John of France, once prisoner in England, came to see the Countess of Salisbury, the nonpareil of those times, and his dear mistress.