A group of closely associated things, especially closely spaced spectral lines or atomic energy levels, or subatomic particles differing only in a single property (e.g. charge or strangeness)
- ‘Saturation was thereby achieved by multiple photon absorption in thymine doublets and multiplets.’
1920s: from multiple, on the pattern of words such as doublet and triplet.
We take a look at several popular, though confusing, punctuation marks.