ter ‧ ri ‧ er /ˈteriə $ -ər/ BrE AmE noun [countable]
[ Date: 1400-1500 ; Language: French ; Origin: (chien) terrier 'earth dog, terrier' , from terrier 'of earth' , from Medieval Latin terrarius , from Latin terra ( ⇨ ↑ terrace ); because it hunts by digging into animals' holes ]
a small active type of dog that was originally used for hunting