ˌ ̷ ̷ ̷ ̷ ̷ ̷ˈlaksə̇s noun
( plural tachyphylax·es -kˌsēz)
Etymology: New Latin, from tachy- + -phylaxis (as in prophylaxis )
: diminished response to later increments in a sequence of applications of a physiologically active substance (as the diminished pressor response that follows repeated injections of renin)