Word Study
altostratus
CIDE DICTIONARY
altostratus, n. [L. altus high + L. & E. stratus.].
A cloud formation similar to cirro-stratus, but heavier and at a lower level; a stratus cloud at an intermediate altitude of 2 or 3 miles. [Webster 1913 Suppl.]
OXFORD DICTIONARY
altostratus, n. (pl. altostrati) a continuous and uniformly flat cloud formation at medium altitude.
Etymology
mod.L f. L altus high + STRATUS
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