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"Chiquita" is a form of "chiquito", an adjective which is often translated as "tiny". "Muñeco" is a noun which is often translated as "doll". Learn more about the difference between "chiquita" and "muñeco" below.
chiquito(
chee
-
kee
-
toh
)An adjective is a word that describes a noun (e.g., the big dog).
A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
a. small glass of wine 
¡Mesero! Dos chiquitos y una cerveza, por favor.Waiter! Two small glasses of wine and a beer, please.
el muñeco, la muñeca(
moo
-
nyeh
-
koh
)This means that the noun can be masculine or feminine, depending on the gender of the noun it refers to (e.g., el doctor, la doctora).
1. (toy)
a. doll 
Este es el muñeco de trapo con el que jugaba mi abuela de chica.This is the rag doll my grandmother played with when she was a child.
2. (colloquial) (pretty person)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
a. sweetie  (colloquial)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
¿Ese niño con el trajecito es tu hijo? ¡Qué muñeco!That kid in the little suit is your son? What a sweetie!
3. (colloquial) (wimp)
A word or phrase that is commonly used in conversational speech (e.g., skinny, grandma).
a. puppet 
Su jefe se aprovecha de él porque es un muñeco.His boss takes advantage of him because he is a puppet.
A masculine noun is used with masculine articles and adjectives (e.g., el hombre guapo, el sol amarillo).
a. toy 
El bebé está jugando con sus muñecos en el corralito.The baby is playing with his toys in the playpen.
a. dummy 
El ventrílocuo usó dos muñecos para su rutina de comedia.The ventriloquist brought two dummies for his comedy act.
a. puppet 
El titiritero movía dos muñecos al mismo tiempo.The puppeteer did two puppets at the same time.
7. (drawing)
a. figure 
Mira el muñeco y señala dónde está el hígado.Look at the figure and point out where the liver is.
a. effigy 
Los miembros de la oposición colgaron un muñeco del primer ministro.Opposition members hanged an effigy of the prime minister.