IshGen 169:17 :ܘܠܐ ܬܒܬܗܘܢ ܘܠܐ ܬܦܫܘܪܬܗܘܢ ܢܦܩ̈ܢ ܗܘ̈ܝ‏ : neither their excrement nor their urine would excrete
See the entire entry for *tḇeṯ, teḇtā n.f. excrement