tam·per·proof 
(tămpər-prf′)
(tămpər-prf′)adj.
Designed to prevent tampering or provide evidence of tampering: tamperproof aspirin containers.
- first down
- first edition
- first family
- first finger
- first floor
- first fruits
- firstfruits
- first-generation
- first gentleman
- firsthand
- first home
- first-in, first-out
- first lady
- first lieutenant
- first-line
- firstling
- firstly
- first mate
- first name
- First Nation
- First Nations
- first night
- first off
- first offender
- first off/thing