Lewis & Short

ārĭdĭtas, ātis, f. [aridus], dryness, drought.

  1. I.
    1. A. Lit.: ariditatem ampliare, Plin. 11, 35, 41, § 117: myrtus siccata usque in ariditatem, id. 15, 29, 37, § 123: ariditas aquae, Vulg. Judith, 11, 10.
      In the plur.: ariditatibus temperamenta ferre, Arn. 2, 69.
    2. B. In Pall. meton. (abstr. pro concr.), any thing dry, withered, or parched: cum fimi ariditate miscenda est, i. e. fimo arido, Pall. 3, 4: ariditatem recidere, the dry, dead wood, id. 3, 21, 2.
  2. II. Trop., a being withered, dryness: stipula ariditate plena, Vulg. Nah. 1, 10: bracchium ejus ariditate siccabitur, ib. Zach. 11, 17; and meton. (abstr. for concr.), of meagre, scanty food, Salv. 1, 1 sq.