Have a look here http:/dictionary.reference.com/browse/viscous
Viscosity it how thick or thin a fluid is.
The thicker a fluid is the more viscous. If the fluid is less viscous it is thinner. A fluid is liquid AND gas. If a fluid is hotter is gets less viscous but if it is cooler it will be more viscous.
View page
it mean that it can not be compressed
View page
no
View page
Viscosity is defined as a measure of the resistance to flow of a
fluid. Therefor, the flow of, or the passage of an object through,
a viscous fluid is resisted by the fluid.