QUICK ANSWER
"Un" is an indefinite article which is often translated as "a", and "cola" is a noun which is often translated as "tail". Learn more about the difference between "un" and "cola" below.
un(
oon
)An indefinite article is a word that indicates that a noun is not specific (e.g., a girl).
1. (singular)
b. an (before vowel sound)
Tienen una vieja cámara que todavía funciona.They have an old camera which is still working.
la cola(
koh
-
lah
)A feminine noun is almost always used with feminine articles and adjectives (e.g., la mujer bonita, la luna llena).
b. queue (United Kingdom)
Regionalism used in the United Kingdom
El vendedor quiere que nos pongamos en cola.The salesman wants us to form a queue.
3. (clothing)
5. (substance)
6. (beverage) (Dominican Republic) (Ecuador) (El Salvador)
Regionalism used in the Dominican Republic
Regionalism used in Ecuador
Regionalism used in El Salvador
7. (colloquial) (buttocks) (Latin America)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
Regionalism used in Latin America: all the countries in South America, Central America, and the Caribbean. Does not include Spain.
a. butt (colloquial) (United States)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
Regionalism used in the United States
La cola de la bebé está irritada.The baby's butt is irritated.
b. bum (colloquial) (United Kingdom)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
Regionalism used in the United Kingdom
Había agua en el banco donde me senté. Ahora tengo la cola mojada.There was water on the bench where I sat down. Now my bum is wet.
8. (colloquial) (penis) (Spain)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
Regionalism used in Spain
a. weenie (colloquial) (United States)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
Regionalism used in the United States
Mamá, a ese niño se le ve la cola.Mom, I can see that boy's weenie.
b. willy (colloquial) (United Kingdom)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
Regionalism used in the United Kingdom
El bebé llora cuando hace pipí. Creo que le escuece la cola al pobrecito.The baby cries when he's peeing. I think his willy stings, poor thing.