ambo

https://doi.org/10.1351/goldbook.A00261
A prefix used to indicate that a molecule with two (or more) chiral elements is present as a mixture of the two racemic diastereoisomers in unspecified proportions. For example, the dipeptide formed from l-alanine and dl-leucine is l-alanyl-ambo-leucine.
Source:
PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2198 (https://doi.org/10.1351/pac199668122193)
See also:
PAC, 1982, 54, 1507. 'Nomenclature of Tocopherols and Related Compounds' on page 1507 (https://doi.org/10.1351/pac198254081507)
PAC, 1984, 56, 595. 'Nomenclature and Symbolism for Amino Acids and Peptides' on page 595 (https://doi.org/10.1351/pac198456050595)