A long, elastic strand of mucus that dangles from a sick child's nostril when the child cries. This slimy yo-yo often gets sucked up into the nose when the child inhales between shrieks, only to reappear when the wailing continues. Since it's entertaining for adults to watch this, the child assumes your expression of delight is in response to their distress, which only increases the volume and intensity of the tantrum. It's a viscious (and viscous) cycle which might end on a clock-tower with a high-powered rifle.
A person to which one goes to in order to ensure a healthy and prosperous pair of nostrils. At the nostrologist, one can get a nostrilectomy, a nostril cleaning, or nostril pastic surge, to rid oneself of unsightly hairs and nostril blemishes.
Nostrovia is a miss-pronunciation of Russian word Na Zdorovie (На здоровье) which is traditionally used as a commontoast meaning To good health or simply Cheers.