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
- live a lie
- live a little
- live action
- live album
- live and breathe
- live and learn
- live and let live
- live at home
- live axle
- live beyond one's means
- live birth
- live by
- live by one's wits
- live coverage
- live down
- live for
- live happily ever after
- live hole
- live in a fantasy world
- live in each other's pockets
- live in fear
- live in hope
- live in sin
- live in the past
- live it up