ACID [as-id] What it is: Substances with a pH value less than 7. The opposite of alkaline. VIDEOS RELATED TO THIS TERMInside the Julie K Nail ArtelierSarah PetersenGelish Cover Tips LEARN MORE TERMSOMBRÉMATTE TOP COATCURETTEIMPLEMENTSC-CURVEINSURANCEBRUISED NAILCOATINGDUST COLLECTORRUSSIAN ALMONDPEDICUREMIXED MEDIASIDEWALLAUTOCLAVEDIP SYSTEMGLITTER NAILSLED LAMPGELANALOGOUS COLORSHOLOGRAPHICOMBRÉMATTE TOP COATCURETTEIMPLEMENTSC-CURVEINSURANCEBRUISED NAILCOATING PrevNext