Thaïs is from the Greek Thais — possibly meaning "bandage" or "loved one"; the historical Thaïs was a 4th-century BCE Greek hetaira who accompanied Alexander the Great. Thaïs (1894 opera) — Jules Massenet's opera based on the France novel; the "Méditation" — the violin solo that plays between acts — is one of the most-performed pieces in the violin repertoire (Yo-Yo Ma, Itzhak Perlman, and Joshua Bell have all recorded it). Thaïs Carla — French personality. The name reflects the broader 21st-century vintage-Greek revival.
Thaïs does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Thaïs reduce to 2, The Peacemaker. This is a traditional interpretive system, not a factual claim about the name.