a device that signals the occurrence of some undesirable event
an automatic signal (usually a sound) warning of danger
fear resulting from the awareness of danger
warn or arouse to a sense of danger or call to a state of preparedness; "The empty house alarmed him"; "We alerted the new neighbors to the high rate of burglaries"
the quality of being difficult to do; "he assigned a series of problems of increasing hardness"; "the ruggedness of his exams caused half the class to fail"
the property of being rigid and resistant to pressure; not easily scratched; measured on Mohs scale
the fundamental assumptions from which something is begun or developed or calculated or explained; "the whole argument rested on a basis of conjecture"
the most important or necessary part of something; "the basis of this drink is orange juice"
so thin as to transmit light; "a hat with a diaphanous veil"; "filmy wings of a moth"; "gauzy clouds of dandelion down"; "gossamer cobwebs"; "sheer silk stockings"; "transparent chiffon"; "vaporous silks"