Breastfeeding Glossary: Terms to Know

Breastfeeding Glossary: Terms to Know

When it comes to having a baby, sometimes it feels like you’re learning something new every other minute, with breastfeeding being no exception.

Like, one day your friends are telling you about this amazing thing called a milk collector you should check out and the next, nurses are explaining cluster feeding to you while you’re barely awake in the hospital.

To help keep things easy and simple, we’ve put together a breastfeeding glossary of common breastfeeding terms and devices all in one spot. Here’s what to know:


the circular area of pigmented skin surrounding a nipple

Breast crawl

when a newborn is placed skin-to-skin on their mother’s chest and instinctually moves toward the nipple to initiate breastfeeding 

Breast milk

milk produced by human mammary glands

Breast milk expression

the act of removing milk from a breast, either by hand or pump

Breast milk storage bag

a small, airtight container that stores expressed breast milk for later use, usually in the fridge or freezer

Breast pump

a device for extracting and collecting milk from a breast during lactation that uses suction


the act of feeding a baby with milk from the breast

Breastfeeding pillow

a nursing pillow made specifically to help cradle a baby while being breastfed

Clogged/blocked milk duct

when a milk duct in the breast becomes narrow from not enough milk drainage, causing inflammation or swelling

Cluster feeding

when a baby eats in consecutive sessions for shorter periods of time


a thick, yellowish-white fluid that develops during pregnancy and is secreted from the breasts during the first few days after giving birth


when a breast is overly full with milk that can cause swelling, tenderness and pain

Expressed breast milk

milk expressed by hand or pump (manual or electric); milk is then placed in a receiving vessel and may be transferred to another vessel or stored before being fed to the recipient infant

Exclusive pumping

when a baby is only fed breast milk that is expressed or pumped


the funnel part of a breast pump that is placed over the breast and nipple to form a seal for suction


the milk released at the beginning of a feeding when breasts are full

Hand expression

expressing breast milk by hand


the milk released at the end of a feeding, which usually has a higher fat content

Inverted nipple

when a nipple points inward and lies flat instead of pointing out


the process of producing and releasing milk by the mammary glands in a breast


the release of milk from the breast causing the milk to flow out


how a baby attaches to the breast while breastfeeding

Leaking breast milk

a normal pregnancy or postpartum symptom where breast milk leaks, drips or sprays milk due to the letdown reflex


inflammation of tissue in the breast, often caused by an infection

Milk collector

a device that helps collect breast milk leaking or flowing from the breast that can be used for later feedings


a small projection on the breast that breast milk can pass through

Nipple shield

a silicone device worn over the nipple and areola to help a baby latch on to the nipple while nursing

Nursing pad

a pad placed inside a bra or tank to help absorb leaking breast milk

Tandem feeding

breastfeeding two or more children of different ages at the same time


Looking for more about breastfeeding? Check out our tips for pumping exclusively here or breastfeeding after a c-section here.

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