Noun
trickler (plural tricklers)
An outlet in the microtubing used in drip irrigation.
Competition shooters will generally throw a slightly underweight charge, and use a powder trickler to add few granules of powder at a time to the charge to bring it to the exact weight desired for maximum consistency. Source: Internet
With a powder trickler, a charge can be measured directly into the scale, giving the most accurate measure. Source: Internet