Translation guide
The small projection on the breast. In Japanese, the word differs for humans vs. animals, and for the anatomical part vs. the part of a baby bottle.
nipple (human)
nipple (baby bottle)
Same word as human nipple; context clarifies.
The most common and neutral word for a human nipple. Used in everyday conversation and medical contexts.
The baby is sucking on the nipple.
A more formal, anatomical term for nipple. Often used in medical or technical contexts.
There are individual differences in nipple shape.
The nipple of an animal, especially livestock.
Can be used for animals as well, though it may sound slightly anthropomorphic. Commonly used for pets.
The number of nipples varies from dog to dog.
Refers to the udder or teat of livestock, especially cows. Often used in agricultural contexts.
The rubber or silicone part of a baby bottle that the baby sucks on.
Also used for the artificial nipple of a baby bottle. Context makes the meaning clear.
Please sterilize the nipple of the baby bottle.
The word 乳 (ちち) can mean 'milk' or 'breasts' in general, but not specifically 'nipple'. Use 乳首 (ちくび) for nipple.
牛の乳房を消毒する。
Disinfect the cow's teats.