1
- the eighth letter of the Greek alphabet (Θ, θ), transliterated as 'th'希腊字母表中第八个字母（ 译写为th）。
1.1
Theta
followed by Latin genitive Astronomy the eighth star in a constellation【天文】θ星（星座中第八颗星）：Theta Draconis.
天龙座θ星。
1.2
- as modifier Chemistry denoting a temperature at which a polymer solution behaves ideally as regards its osmotic pressure【化】θ温度。
1.3
- as modifier denoting electrical activity observed in the brain under certain conditions, consisting of oscillations having a frequency of 4 to 7 hertz.θ节律：
theta rhythm.
θ节律。
1.1
θ
temperature (especially in degrees Celsius)温度（尤指摄氏度）。
1.2
θ
a plane angle飞机角度。
1.3
θ
a polar coordinate. Often coupled with φ.极坐标（常与φ成对使用）。
词源
Greek.