wavelength, \(\lambda\)

Distance in the direction of propagation of a periodic wave between two successive points where at a given time the phase is the same.
Green Book, 2nd ed., p. 30 (https://dev.goldbook.iupac.org/files/pdf/green_book_2ed.pdf)
ISO 31-05: 1992 (http://www.iso.org/iso/catalogue_detail.htm?csnumber=3635)
PAC, 1996, 68, 957. 'Glossary of terms in quantities and units in Clinical Chemistry (IUPAC-IFCC Recommendations 1996)' on page 998 (https://doi.org/10.1351/pac199668040957)