cirrus
UK[ˈsɪrəs]US[ˈsɪrəs]
n
a type of thin, wispy cloud that forms at high altitude
n
a slender tendril or filament, such as a plant's tendril or a slender appendage in some animals
Etymology
the word 'cirrus' is a direct borrowing from latin, where it meant a 'curl' or 'lock of hair'. this latin term is believed to be derived from the proto-indo-european root sker- or ker-, meaning 'to turn' or 'to bend', a root which also gives rise to words like 'ring', 'curve', and 'crown'. the application to meteorology in the late 18th century was a direct metaphorical extension, as the wispy, fibrous appearance of these high-altitude clouds resembles curled hair. thus, the term's journey from a concrete physical description in latin to a specific scientific classification in english demonstrates a clear and logical semantic evolution based on visual resemblance.
Analysis
the word is a simplex loanword from latin. it is not productively formed from smaller, recognizable morphemes within modern english spelling.
Examples
delicate cirrus clouds streaked the pale blue sky.
the forecast predicts the arrival of cirrus, often a precursor to a change in weather.
under the microscope, the parasite was identified by the fine cirri at its posterior end.