plural of reference frame

(physics) Alternative form of frame of reference

A reflector with a curved reflecting surface that forms part of a paraboloid (as opposed to, for example, a sphere)

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

Alternative form of ultrarefined

(medicine) The reflux of urine from one moiety of the kidney down the ureter and up into the other moiety, instead of draining into the bladder.

(grammar, linguistics) A deliberate, often authoritatively sanctioned or mandated change to spelling rules.

(medicine) A non-invasive test used to diagnose congestive heart failure.

(medicine) A disorder with intense burning pain, one of two types of complex regional pain syndrome.

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