ˈθɪərɪ n. (pl. -ies) 1 a
supposition or
system of ideas explaining
something,
esp.
one based on
general principles
independent of
the particular things to be explained (opp. HYPOTHESIS) (atomic theory; theory of evolution). 2 a
speculative (esp. fanciful)
view (one of my pet theories). 3 the
sphere of
abstract knowledge or speculative thought (this is
all very well in theory, but how will it
work in practice?). 4 the
exposition of the principles of a
science etc. (the theory of music). 5
Math. a
collection of propositions to
illustrate the principles of a
subject (probability theory; theory of equations). [LL theoria f. Gk theoria f. theoros
spectator f. theoreo
look at]