| obuvníkshoemakerSubstantiv | Substantiv |
| obvazbandageSubstantiv | Substantiv |
| obviněnýaccused personSubstantiv | Substantiv |
| obvodperimeterSubstantiv | Substantiv |
| obvykleusuallyAdverb | Adverb |
| obvyklýusualAdjektiv | Adjektiv |
| obyčejněusually; by ordinary mailAdverb | Adverb |
| obyčejnýordinaryAdjektiv | Adjektiv |
| obývacíliving-roomAdjektiv | Adjektiv |
| obývákliving roomSubstantiv | Substantiv |
| obyvatelinhabitantSubstantiv | Substantiv |
| obžalovanýdefendantSubstantiv | Substantiv |
| ocelsteelSubstantiv | Substantiv |
| očařeye doctorSubstantiv | Substantiv |
| očekávatexpectVerb | Verb |
| očieyesSubstantiv | Substantiv |
| očkovacívaccinationAdjektiv | Adjektiv |
| očkovánívaccinationSubstantiv | Substantiv |
| očníeyeAdjektiv | Adjektiv |
| odfrom, sincePräposition | Präposition |
| odbavenícheck-in; processingSubstantiv | Substantiv |
| odbavit secheck inVerb | Verb |
| odbočitturn off; turnVerb | Verb |
| odbočkaturn-off; turningSubstantiv | Substantiv |
| odbočovatbe turning; turn repeatedlyVerb | Verb |
| odbordepartment; office sectionSubstantiv | Substantiv |
| odborněprofessionally, expertlyAdverb | Adverb |
| odbornýexpert; professional; technicalAdjektiv | Adjektiv |
| oddělenídepartment; wardSubstantiv | Substantiv |
| odejítleave; go awayVerb | Verb |
| odesílatelsenderSubstantiv | Substantiv |
| oděvgarment; clothing itemSubstantiv | Substantiv |
| odcházetleave; go awayVerb | Verb |
| odjetleave; depart by vehicleVerb | Verb |
| odjezddepartureSubstantiv | Substantiv |
| odjíždětleave; depart by vehicleVerb | Verb |
| odkazlinkSubstantiv | Substantiv |
| odkázatbequeath; leave to someoneVerb | Verb |
| odkdysince when, from whenAdverb | Adverb |
| odkládatpostpone; put offVerb | Verb |
| odkudfrom whereAdverb | Adverb |
| odletflight departureSubstantiv | Substantiv |
| odletětfly away; depart by airVerb | Verb |
| odlišnýdifferentAdjektiv | Adjektiv |
| odložit sitake off clothingVerb | Verb |
| odměnareward; remunerationSubstantiv | Substantiv |
| odmítatrefuseVerb | Verb |
| odmítnoutrefuse; rejectVerb | Verb |
| odněkudfrom somewhereAdverb | Adverb |
| odnéstcarry away; take awayVerb | Verb |
| odnikudfrom nowhere, not from anywhereAdverb | Adverb |
| odpadwasteSubstantiv | Substantiv |
| odpadkygarbageSubstantiv | Substantiv |
| odpočinout sirest; relaxVerb | Verb |
| odpočívatrest; relaxVerb | Verb |
| odpolednein the afternoon, afternoonAdverb | Adverb |
| odpoledníafternoonAdjektiv | Adjektiv |
| odpověďanswerSubstantiv | Substantiv |
| odpovědětanswerVerb | Verb |
| odpovídatanswer; answer regularlyVerb | Verb |
| odtáhnoutpull away; tow awayVerb | Verb |
| odtamtudfrom thereAdverb | Adverb |
| odtudfrom hereAdverb | Adverb |
| odvážnýbrave; boldAdjektiv | Adjektiv |
| odvéstlead away; take awayVerb | Verb |
| odvézttake away by vehicle; drive awayVerb | Verb |
| ohlásitreport; announce; registerVerb | Verb |
| ohňostrojfireworks displaySubstantiv | Substantiv |
| ohodnocenívaluationSubstantiv | Substantiv |
| oholit seshave oneselfVerb | Verb |
| ochotawillingnessSubstantiv | Substantiv |
| ochranaprotectionSubstantiv | Substantiv |
| ochutnattaste; try food or drinkVerb | Verb |
| ochutnávattaste; sample repeatedlyVerb | Verb |
| ojetýused; worn (esp. car)Adjektiv | Adjektiv |
| okamžitěimmediatelyAdverb | Adverb |
| oknowindowSubstantiv | Substantiv |
| okoeyeSubstantiv | Substantiv |
| okolísurroundingsSubstantiv | Substantiv |
| okopírovatcopyVerb | Verb |
| okresnídistrictAdjektiv | Adjektiv |
| okupaceoccupationSubstantiv | Substantiv |
| okurkacucumberSubstantiv | Substantiv |
| okurkovýcucumberAdjektiv | Adjektiv |
| olejoilSubstantiv | Substantiv |
| olovoleadSubstantiv | Substantiv |
| olympiádaOlympicsSubstantiv | Substantiv |
| omáčkasauceSubstantiv | Substantiv |
| omezenýlimited; restrictedAdjektiv | Adjektiv |
| omlouvat seapologise; apologizeVerb | Verb |
| omluvit seapologiseVerb | Verb |
| omylmistakeSubstantiv | Substantiv |
| onhePronomen | Pronomen |
| onashePronomen | Pronomen |
| opačnýoppositeAdjektiv | Adjektiv |
| opakovatrepeatVerb | Verb |
| opalovánítanningSubstantiv | Substantiv |
| opalovat sesuntanVerb | Verb |
| operaoperaSubstantiv | Substantiv |
| operaceoperationSubstantiv | Substantiv |