[ ˌaskə'mʌɪsi:t ]
■ noun ( plural ~s -'mʌɪsi:ts , -mʌɪ'si:ti:z ) Botany a fungus of a large group whose spores develop within asci (sacs) and which includes most moulds, mildews, and yeasts, the fungal component of most lichens, and the morels and truffles.
Origin
C19: from mod. L. Ascomycetes (former class name), from Gk askos 'sac' + mukētes 'fungi'.