cirro-, cirr-, cirri- +

(Latin: curl, ringlet; tuft of hair, fringe; by extension, filament, tendril)

1. Bearing a tendril or tendrils; such as, a cirrose leaf.
2. Resembling a tendril or cirrus.
Tufted; said of certain feathers of birds.
cirrus (s), cirri (pl)
1. A thin wispy cloud, occurring as narrow bands of tiny ice particles, that forms at the highest and coldest point of the cloud region.
2. A slender tentacle with sensory or locomotive function, or a part resembling one.
3. A filament or slender appendage serving as a foot, tentacle, barbel, etc.
4. The male copulatory organ of flatworms and various other invertebrates.
5. A slender flexible animal appendage; such as, those on barnacles or crinoids or many insects; often tactile.
6. A structure formed from a cluster of tuft of fused cilia, constituting one of the sensory or locomotor organs of certain ciliate protozoa.
cirrus spissatus; cirrus densus, cirrus nothus; thunderstorm cirrus, false cirrus
A cloud species which is unique to the genus cirrus, of such optical thickness as to appear grayish on the side away from the sun, and to veil the sun, conceal its outline, or even hide it completely.

Cirrus clouds are composed of small particles, mostly ice crystals, that are fairly widely dispersed, usually resulting in relative transparency and whiteness and often producing a halo phenomena (colored or whitish rings, arcs, pillars or spots of light) which are not observed with other cloud forms.