Θ U+0398, Θ GREEK CAPITAL LETTER THETA ← Η [U+0397] Greek and Coptic Ι → [U+0399]

Θ

1. (set theory) Θ, the ordinal number with the same cardinality as the smallest set larger than the real numbers; the smallest nonzero ordinal number such that there exists no surjection onto it from the real numbers.
2. (physics) A pentaquark.
3. (speech pathology) Protruded tongue.

From Phoenician 𐤈 (ṭ, “ṭēt”).

Θ • (Th) (uppercase, lowercase θ)

1. The letter theta (θῆτα), the eighth letter of the ancient Greek alphabet.

• (Cyrillic) Ѳ
• (Coptic) Ⲑ

• (Greek-script letters) Α α, Β β, Γ γ, Δ δ, Ε ε, Ζ ζ, Η η, Θ θ, Ι ι, Κ κ, Λ λ, Μ μ, Ν ν, Ξ ξ, Ο ο, Π π, Ρ ρ, Σ σ ς, Τ τ, Υ υ, Φ φ, Χ χ, Ψ ψ, Ω ω
• (non-Classical letters) Ϝ ϝ, Ͷ ͷ, Ͱ ͱ, Ϻ ϻ, Ϙ ϙ, Ͳ ͳ
• (punctuation) · ;
• (diacritics) ᾿ ῾ ◌́ ◌̀ ῀ ¨

Θ • (Th) (uppercase, lowercase θ)

1. The upper case letter theta (θήτα), the eighth letter of the modern Greek alphabet.

Θ • (Th)

1. The number nine in Greek numerals.

• ,Θ (,Th, “The number 9000 in Greek numerals”)

• Ѳ, ѳ

• (Greek-script letters) Α α, Β β, Γ γ, Δ δ, Ε ε, Ζ ζ, Η η, Θ θ, Ι ι, Κ κ, Λ λ, Μ μ, Ν ν, Ξ ξ, Ο ο, Π π, Ρ ρ, Σ σ ς, Τ τ, Υ υ, Φ φ, Χ χ, Ψ ψ, Ω ω
• (non-Classical letters) Ϝ ϝ, Ͷ ͷ, Ͱ ͱ, Ϻ ϻ, Ϙ ϙ, Ͳ ͳ
• (punctuation) · ;
• (diacritics) ᾿ ῾ ◌́ ◌̀ ῀ ¨

• IPA^(key): /θ/

Θ (lower case ϑ)

1. A letter of the Wakhi alphabet, written in the Latin script.