According to the most common definition, idioms are linguistic express
ions whose overall meaning cannot be predicted from the meanings of th
e constituent parts. Although we agree with the traditional view that
there is no complete predictability we suggest that there is a great d
eal of systematic conceptual motivation for the meaning of most idioms
. Since most idioms are based on conceptual metaphors and metonymies,
systematic motivation arises from sets of 'conceptual mappings or corr
espondences' that obtain between a source and a target domain in the s
ense of Lakoff and Kovecses (1987). We distinguish among three aspects
of idiomatic meaning. First, the general meaning of Idioms appears to
be determined by the particular 'source domains' that apply to a part
icular target domain. Second, more specific aspects of idiomatic meani
ng are provided by the 'ontological mapping' that applies to a given i
diomatic expression. Third, connotative aspects of idiomatic meaning c
an be accounted for by 'epistemic correspondences'. Finally, we also p
resent an informal experimental study the results of which show that t
he cognitive semantic view can facilitate the learning of idioms for n
on-native speakers.