an exciting and mysterious quality (as of a heroic time or adventure)
a movement in literature and art during the late 18th and early 19th centuries that celebrated nature rather than civilization; "Romanticism valued imagination and emotion over rationality"
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