ūdus

1. Uvidum and udum (ὑάς, vadum, from ὕω, uveo) denote, like ὑγρόν, the wetness which consists entirely of water or other fluid particles, whether actually, apparently, or only by hyperbole, humore constans; whereas humidum and humectum (from χυμός) is the wetness which is caused by water soaking through, humore mixtum. Senec. N. Q. ii. 25. Dicis nubes attritas edere ignem cum sint humidæ, imo udæ. Hence is udus (in opp. to sudus and solidus) used by Tertullian as synonymous with aquanus; whereas humidus (in opp. to aridus) is synonymous with aquosus, only that by aquosus is meant a separation and juxta-position of wet and dry; by humidus, a mixture and association of wet and dry; hence pratum aquosum means a meadow with ponds and puddles; pratum humidum, a meadow soaked with water. 2. Udus is only a contracted form of uvidus; humectus is distinguished from humidus only as a sort of participle. Pacuv. ap. Varr. Terra exhalabat auroram humidam, humectam. 3. Humidus, humens, refer, like moist, to the inward quality of a body; whereas madidus, madens, like μυδαλέος and dripping, only to the exterior and surface of a body, in opp. to siccus. Cic. Phil. xiv. 3. Imbuti sanguine gladii legionum exercituumque nostrorum, vel madefacti potius duobus consulum, tertio Cæsaris prœlio; for imbuere, as the causative of imbibere, refers to a humectatio, a moisture of the inner part; madefieri, to a redundatio, the cause of which lies in this, that the inner part is so over-full, that nothing further can be forced into it. (ii. 12.)