Entry 2 senses · 2 variants Webster, 1913 Irrorate · Ir·ro·rate · IPA v. t. a. 01 v. t. To sprinkle or moisten with dew; to bedew. imp. & p. p. Irrorated; p. pr. & vb. n. Irrorating 1. To sprinkle or moisten with dew; to bedew.[Obs.] 02 a. Covered with minute grains, appearing like fine sand. 1. Covered with minute grains, appearing like fine sand.(Zool.)