The act of self-reflecting / The result of self-reflecting (e.g. a thought, statement)

(geometry) In Euclidean geometry, an ordinary reflection not requiring that the reflection be performed using perpendiculars.

(optics) total internal reflection

(optics, uncountable) A phenomenon where light, instead of passing into a medium of a lower refractive index and refracting away from the normal, is completely reflected by the boundary between the two media because it approaches at an angle greater than or equal to the critical angle.

(computer security) A cross-site scripting attack where the malicious script is relayed to the victim in an e-mail or as a URL parameter.