Xerostoma lead me to a new, to me, and rare Latin verb seresco 'to grow dry'. Used by Lucretius to refer to clothes drying (out in the sun)': vestes serescunt, Lucr. I.306. Verbs with -esc- verbal suffix are called inchoatives, e.g., rubesco 'to grow red, turn red, redden', pallesco 'to grow pale'; in English inchoatives tend to end in -en, like redden, coarsen, weaken, etc.