the quality of being difficult; "they agreed about the difficulty of the climb"
a factor causing trouble in achieving a positive result or tending to produce a negative result; "serious difficulties were encountered in obtaining a pure reagent"
a condition or state of affairs almost beyond one's ability to deal with and requiring great effort to bear or overcome; "grappling with financial difficulties"
an unstable construction with playing cards; "he built three levels of his cardcastle before it collapsed"
a speculative scheme that depends on unstable factors that the planner cannot control; "his proposal was nothing but a house of cards"; "a real estate bubble"
a fluid necessary for the life of most animals and plants; "he asked for a drink of water"
binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent
once thought to be one of four elements composing the universe (Empedocles)
secrete or form water, as tears or saliva; "My mouth watered at the prospect of a good dinner"; "His eyes watered"
supply with water, as with channels or ditches or streams; "Water the fields"
not easily borne; wearing; "the burdensome task of preparing the income tax return"; "my duties weren't onerous; I only had to greet the guests"; "a taxing schedule"
an ancient musical horn made from the horn of a ram; used in ancient times by the Israelites to sound a warning or a summons; used in synagogues today on solemn occasions
mutability in life or nature (especially successive alternation from one condition to another)
a variation in circumstances or fortune at different times in your life or in the development of something; "the project was subject to the usual vicissitudes of exploratory research"
corrupt, debase, or make impure by adding a foreign or inferior substance; often by replacing valuable ingredients with inferior ones; "adulterate liquor"
a mechanism consisting of a metal honeycomb through which hot fluids circulate; heat is transferred from the fluid through the honeycomb to the airstream that is created either by the motion of the vehicle or by a fan
heater consisting of a series of pipes for circulating steam or hot water to heat rooms or buildings