Definitions by Apexkilla

lacting up 

When a breastfeeding woman's breasts are bothering her as in being sore or uncomfortable in any way due to milk production.

My wife's left breast has been sore and not producing enough milk for baby these last few days. I wish it would stop lacting up so that I don't have to hear her whine anymore.

lacting up by Apexkilla December 23, 2010