reversion spectroscope
now chiefly historical
noun
A spectroscope in which two spectra (one of which is optically reversed) are formed alongside each other, their alignment being used to determine the proportion of a particular substance within a mixture through comparison with the spectral alignment from the pure substance.
Origin
Mid 19th century. After German Reversionsspectroskop.
- put-off
- put off the evil day (or hour)
- put-on
- put one over on
- put one's affairs in order
- put one's back into
- put one's best foot forward
- put oneself in another's place
- put one's face on
- put one's feet up
- put one's finger in the dyke
- put one's finger on something
- put one's foot down
- put one's foot in it (or put one's foot in one's mouth)
- put one's hand in one's pocket
- put one's hands together
- put one's hands up
- put one's head in a noose
- put one's money where one's mouth is
- put one's shirt on
- put one's shoulder to the wheel
- put on flesh
- putonghua
- put on one's thinking cap
- put on (or lose) weight