| Noun | 1. | lactation - the period following birth during which milk is secreted; "lactation normally continues until weaning"period, period of time, time period - an amount of time; "a time period of 30 years"; "hastened the period of time of his recovery"; "Picasso's blue period" | |
| 2. | lactation - the production and secretion of milk by the mammary glands | |
| 3. | lactation - feeding an infant by giving suck at the breast | |