a tentative theory about the natural world; a concept that is not yet verified but that if true would explain certain facts or phenomena; "a scientific hypothesis that survives experimental testing becomes a scientific theory"; "he proposed a fresh theory of alkalis that later was accepted in chemical practices"
a proposal intended to explain certain facts or observations
a word that expresses a meaning opposed to the meaning of another word, in which case the two words are antonyms of each other; "to him the antonym of `gay' was `depressed'"
the prescribed procedure for conducting religious ceremonies
of or relating to or employed in social rites or rituals; "a ritual dance of Haiti"; "sedate little colonial tribe with its ritual tea parties"- Nadine Gordimer
of or relating to or characteristic of religious rituals; "ritual killing"
any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter
a cavity or passage in a tubular organ; "the lumen of the intestine"
a unit of luminous flux equal to the amount of light given out through a solid angle of 1 steradian by a point source of 1 candela intensity radiating uniformly in all directions
an establishment consisting of a building or complex of buildings where an organization for the promotion of some cause is situated
a custom that for a long time has been an important feature of some group or society; "the institution of marriage"; "the institution of slavery"; "he had become an institution in the theater"
an organization founded and united for a specific purpose
the most favorable environment for a plant or animal; "water is the element of fishes"
a straight line that generates a cylinder or cone
the situation in which you are happiest and most effective; "in your element"
one of four substances thought in ancient and medieval cosmology to constitute the physical universe; "the alchemists believed that there were four elements"