Definition of express verb from the Oxford Advanced Learner's Dictionary
1to show or make known a feeling, an opinion, etc. by words, looks or actionsexpress somethingTeachers have expressed concern about the changes.His views have been expressed in numerous speeches.to express fears/doubts/reservationsto express interest/regret/surpriseexpress how, what, etc…Words cannot express how pleased I am. see also unexpressed2to speak, write or communicate in some other way what you think or feelexpress yourselfTeenagers often have difficulty expressing themselves.express yourself + adverb/prepositionPerhaps I have not expressed myself very well.She expresses herself most fully in her paintings. (formal) express yourself + adjectiveThey expressed themselves delighted.3express itself (+ adverb/preposition) (formal) (of a feeling) to become obvious in a particular wayTheir pleasure expressed itself in a burst of applause.4(mathematics) to represent something in a particular way, for example by symbolsexpress something as somethingThe figures are expressed as percentages.express something in somethingEducational expenditure is often expressed in terms of the amount spent per student.5express something (from something)to remove air or liquid from something by pressing itCoconut milk is expressed from grated coconuts.6express something (to somebody/something) (North American English) to send something by express postAs soon as I receive payment I will express the book to you.