acid-fast
adjective
ac·id-fast ˈa-səd-ˌfast 
: not easily decolorized by acids
Word History
First Known Use
1903, in the meaning defined above
Medical Definition
acid-fast
adjective
ˈas-əd-ˌfast
: not easily decolorized by acids (as when stained) —used especially of bacteria and tissues
- Shepard
- shepardes
- shepards
- shepherd
- shepherd dog
- Shepherd king
- shepherd spider
- shepherd's bag
- shepherd's check
- shepherd's clock
- shepherd's club
- shepherd's coffin
- shepherd's companion
- shepherd's cress
- shepherd's hourglass
- shepherd's needle
- shepherd's pie
- shepherd's pipe
- shepherd's pouch
- shepherd's purse
- shepherd's thyme
- shepherd's weatherglass
- shepherded
- shepherdess
- shepherdesses