taartgat

Etymology
Recent calque of English piehole.

Noun

 * 1)  piehole
 * 2) (when communicating with children) mouth
 * 1) (when communicating with children) mouth
 * 1) (when communicating with children) mouth

Usage notes
Taartgat can be used in a mildly offensive way. While depending on context, the order of offensiveness from least to most offensive will generally be: mond, taartgat, waffel, kop, bek. It can also be used when talking to children in an entertaining way in which case it's not offensive. It can't be used in any formal situations.