ACID-FAST
Meaning of ACID-FAST in English
ˈ ̷ ̷ ̷ ̷ˌ ̷ ̷ adjective
: not easily decolorized by acids (as when stained or dyed) — used especially of bacteria and tissues
Webster's New International English Dictionary.
Новый международный словарь английского языка Webster.
2012