Susceptibility	Sensitivity to a drug, either arresting growth (static drugs) and/or killing cells (cidal drugs).
Fraction of Growth (FoG)	The fraction of growth (FoG) is a measure of tolerance based on assays performed on solid medium. Measured at 48 hours, the growth within the zone of inhibition (and thus above the minimum inhibitory concentration (MIC)) is estimated as a proportion of total growth possible outside the zone of inhibition.
Supra-MIC growth (SMG)	Supra-MIC growth (SMG) is a measure of tolerance based on assays performed in liquid medium. Growth at concentrations above the minimum inhibitory concentration (MIC) is estimated as a proportion of the total growth without drug. SMG provides a quantitative measure of growth similar to some measures of trailing growth.
Fungistatic drugs	Fungistatic drugs inhibit growth but do not necessarily kill a majority of the cell population at concentrations at or above the minimum inhibitory concentration (MIC).
Heteroresistance	Heteroresistance is a clinical term for isolates that contain small subpopulations of cells (generally <1%) that have the ability grow at drug concentrations that are at least 8-times above the minimum inhibitory concentration (MIC) for the vast majority of susceptible cells in the population.
Phenotypic heterogeneity	The expression of different phenotypes in different cells within an isogenic population of cells. For example, some fungal cells grow, while other sister cells do not grow (or grow too slowly to be detected) in the presence of an antifungal drug.
Trailing growth	Trailing growth is generally defined as reduced but persistent visible growth of Candida spp. at fluconazole concentrations above the minimum inhibitory concentration (MIC). Trailing has also been described as an increase in the MIC during growth beyond 24h (the standard endpoint for MIC measurements for Candida species). It can be measured as the residual growth in the presence of fluconazole concentrations above the MIC. Trailing was quantified in a recent study as the percentage of residual yeast growth at fluconazole concentrations above the MIC in each well and mean trailing as the geometric mean of trailing observed in all the wells above the MIC.
Paradoxical growth	Paradoxical growth, also referred to as the Eagle effect, is the ability of a fungal isolate to reconstitute growth in the presence of high drug concentrations, whereas being fully susceptible at lower concentrations. Paradoxical growth appears with a delay of one to several days, but resembles growth in the absence of the drug. Paradoxical growth has been reported primarily for echinocandins.
Adjuvants	A drug that potentiates the effect of an anti-infective, but is not an anti-infective on its own.
Fungicidal activity	Drugs with fungicidal activity reduce a population of cells by >99.9% or 3 log 10 units at a concentration equal to or greater than the minimum inhibitory concentration (MIC).