These are predefined words, so you can think in physics, rather than in html-entity speak. There is some redundancy (many-to-one mappings), as the same greek letter denotes different physical elements in different contexts.
SymbolDelta
SymbolDifferential
SymbolPlusorminus
SymbolPositive
SymbolNegative
SymbolProportion
SymbolEquivalent
SymbolMultipliedby
SymbolMinus
SymbolPlus
SymbolArrowright
SymbolEqual
SymbolApproxequal
SymbolPi
SymbolCopyright
SymbolEndash
SymbolHalf
SymbolQuarter
SymbolAlpha
SymbolBeta
SymbolGamma
SymbolPercent
SymbolDegree
SymbolTemperaturecentigrade
SymbolOhm
SymbolAngle
SymbolAngularv
SymbolAngulara
SymbolWavelength
SymbolDensity
SymbolFlux
SymbolEpsilon
SymbolMu
SymbolSigma
SymbolStrain
SymbolStress
UcAlpha
UcBeta
UcGamma
UcDelta
UcEpsilon
UcZeta
UcEta
UcTheta
UcIota
UcKappa
UcLambda
UcMu
UcNu
UcXi
UcOmicron
UcPi
UcRho
UcSigma
UcTau
UcUpsilon
UcPhi
UcChi
UcPsi
UcOmega
LcAlpha
LcBeta
LcGamma
LcDelta
LcEpsilon
LcZeta
LcEta
LcTheta
LcIota
LcKappa
LcLambda
LcMu
LcNu
LcXi
LcOmicron
LcPi
LcRho
LcSigma
LcTau
LcUpsilon
LcPhi
LcChi
LcPsi
LcOmega
Symbols
Δ
d
±
+
−
∝
≡
×
−
+
→
=
≅
π
©
–
½
¼
α
β
γ
%
°
°C
Ω
θ
ω
α
λ
ρ
Φ
ε
μ
σ
ε
σ
Greek
Α
Β
Γ
Δ
Ε
Ζ
Η
Θ
Ι
Κ
Λ
Μ
Ν
Ξ
Ο
Π
Ρ
Σ
Τ
Υ
Φ
Χ
Ψ
Ω
α
β
γ
δ
ε
ζ
η
θ
ι
κ
λ
μ
ν
ξ
ο
π
ρ
σ
τ
υ
φ
χ
ψ
ω