Meteorol. [a. L. strātus (u stem), f. strā-, sternĕre to spread, lay down. (See quot. 1803, and cf. STRATUM.)] One of the simple forms of cloud, having the appearance of a broad sheet of nearly uniform thickness, usually existing at low elevations.
1803. L. Howard, Modif. Clouds (1865), 4. Stratus.… A widely extended, continuous, horizontal sheet, increasing from below upward. footn. This application of the Latin word stratus is a little forced. But the substantive stratum, did not agree in its termination with the other two [cirrus, cumulus], and is besides already used in a different sense even on this subject, e.g. a stratum of clouds; yet it was desirable to keep the derivation from the verb sterno, as its significations agree so well with the circumstances of this Cloud.
1831. Brewster, Nat. Magic, vi. (1833), 141. A thin stratus or ‘fog bank’ appeared in the same quarter.
1858. Jenyns, Observ. Meteorol., 199. Hence a mist will often appear in damp places, while in others, where dews are of constant occurrence, a mist, i.e. stratus, may be a rare thing.
1882. Pidgeon, Engineer’s Holiday, II. 216. Extending … a considerable distance towards the zenith, lay a thick horizontal layer of stratus, above which was blue.
attrib. 1860. Tyndall, Glac., I. xviii. 122. A gray stratus cloud had drawn itself across the neck of the Matterhorn.
1883. Harper’s Mag., May, 888/2. In that low mass of stratus clouds which overhung the sunset there was now a wild convulsion.
