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Webster 1913 Edition

Adj.

[From

(Chem.)

Of, pertaining to, or derived from, a lactone.

Adj.

[From

(Chem.)

Pertaining to, or designating, an acid obtained by the oxidation of milk sugar (lactose).

lactonic ‎(not comparable)

(organic chemistry) Of, relating to, or derived from, lactone.
a lactonic ester