...• The definition of these words group can be called chunk (词块), collocations(固定搭配), fixed expressions (固定表达式), lexical phrases(词汇短语) and lexical (ized) sentence stems(建造句子词块) • Rodgers & DeCarrico (拉丁格和德卡里科)： ...
Idiomsareaspecialformoflanguage, they are fixedexpressions, whosemeaningcannot alwaysbe readily derived from the usual meaning of itsconstituent elements.