-pet-

WordReference Random House Learner's Dictionary of American English © 2026

pet¹ /pɛt/   n., adj., v., pet•ted, pet•ting. 
n. [countable]

1. an animal kept as a companion in the home:
   She had always wanted a dog as a pet.
2. a person who is especially well cared for or favored:
   a teacher's pet.

adj. [before a noun]

3. kept or treated as a pet:
   two pet canaries.
4. especially well cared for, such as a child.
5. favorite;
   preferred:
   a pet theory.
6. showing fondness or affection:
   pet names for each other, like "Poochie'' and "Boopsie.''

v. 

7. to stroke or touch kindly with the hand:
   [~ + object] She petted the dog on its head.
8. Informal Terms to kiss and touch, stroke, or caress in a way expressing sexual attraction: [~ + object]
   They were petting each other on the sofa.
   [no object]
   They were petting in the back seat of his car.
9. [~ + object] to treat as a pet;
   indulge.

PET /pɛt/  n. [uncountable]

1. Medicine positron emission tomography, a technique for revealing active areas of the brain while information is being processed.

-pet-,² root. 

1. -pet- comes from Latin, where it has the meaning "seek;
   strive for.'' This meaning is found in such words as: appetite, centripetal, compete, competence, competent, competition, impetigo, impetuous, impetus, perpetual, petition, petulant, repeat, repetition.

WordReference Random House Unabridged Dictionary of American English © 2026

pet¹  (pet), n., adj., v., pet•ted, pet•ting. 
n. 

1. any domesticated or tamed animal that is kept as a companion and cared for affectionately.
2. a person especially cherished or indulged;
   favorite:
   He was the teacher's pet.
3. a thing particularly cherished.

adj. 

4. kept or treated as a pet:
   a pet lamb.
5. especially cherished or indulged, as a child or other person.
6. favorite;
   most preferred:
   a pet theory.
7. showing fondness or affection:
   to address someone with pet words.

v.t. 

8. to fondle or caress:
   to pet a dog.
9. Informal Terms to treat as a pet;
   indulge.

v.i. 

10. Informal Terms to engage in amorous fondling and caressing.

• 1500–10; (noun, nominal) perh. back formation from pet lamb cade lamb, shortened variant of petty lamb little lamb (see petty); (verb, verbal) derivative of the noun, nominal

pet′ta•ble, adj. 
Synonyms

• 8. baby, humor, pamper, favor.

pet²  (pet), n. 

1. a fit of peevishness, sulking, or bad mood.

v.i. 

2. to be peevish;
   sulk.

• 1580–90; origin, originally uncertain; compare pettish

PET  (pet), 

1. Medicine positron emission tomography. Cf. PET scan. 

Pet., 

1. Peter.

pet., 

1. Chemistry petroleum.