| obuvníkshoemakerNoun | Noun |
| obvazbandageNoun | Noun |
| obviněnýaccused personNoun | Noun |
| obvodperimeterNoun | Noun |
| obvykleusuallyAdverb | Adverb |
| obvyklýusualAdjective | Adjective |
| obyčejněusually; by ordinary mailAdverb | Adverb |
| obyčejnýordinaryAdjective | Adjective |
| obývacíliving-roomAdjective | Adjective |
| obývákliving roomNoun | Noun |
| obyvatelinhabitantNoun | Noun |
| obžalovanýdefendantNoun | Noun |
| ocelsteelNoun | Noun |
| očařeye doctorNoun | Noun |
| očekávatexpectVerb | Verb |
| očieyesNoun | Noun |
| očkovacívaccinationAdjective | Adjective |
| očkovánívaccinationNoun | Noun |
| očníeyeAdjective | Adjective |
| odfrom, sincePreposition | Preposition |
| odbavenícheck-in; processingNoun | Noun |
| odbavit secheck inVerb | Verb |
| odbočitturn off; turnVerb | Verb |
| odbočkaturn-off; turningNoun | Noun |
| odbočovatbe turning; turn repeatedlyVerb | Verb |
| odbordepartment; office sectionNoun | Noun |
| odborněprofessionally, expertlyAdverb | Adverb |
| odbornýexpert; professional; technicalAdjective | Adjective |
| oddělenídepartment; wardNoun | Noun |
| odejítleave; go awayVerb | Verb |
| odesílatelsenderNoun | Noun |
| oděvgarment; clothing itemNoun | Noun |
| odcházetleave; go awayVerb | Verb |
| odjetleave; depart by vehicleVerb | Verb |
| odjezddepartureNoun | Noun |
| odjíždětleave; depart by vehicleVerb | Verb |
| odkazlinkNoun | Noun |
| odkázatbequeath; leave to someoneVerb | Verb |
| odkdysince when, from whenAdverb | Adverb |
| odkládatpostpone; put offVerb | Verb |
| odkudfrom whereAdverb | Adverb |
| odletflight departureNoun | Noun |
| odletětfly away; depart by airVerb | Verb |
| odlišnýdifferentAdjective | Adjective |
| odložit sitake off clothingVerb | Verb |
| odměnareward; remunerationNoun | Noun |
| odmítatrefuseVerb | Verb |
| odmítnoutrefuse; rejectVerb | Verb |
| odněkudfrom somewhereAdverb | Adverb |
| odnéstcarry away; take awayVerb | Verb |
| odnikudfrom nowhere, not from anywhereAdverb | Adverb |
| odpadwasteNoun | Noun |
| odpadkygarbageNoun | Noun |
| odpočinout sirest; relaxVerb | Verb |
| odpočívatrest; relaxVerb | Verb |
| odpolednein the afternoon, afternoonAdverb | Adverb |
| odpoledníafternoonAdjective | Adjective |
| odpověďanswerNoun | Noun |
| odpovědětanswerVerb | Verb |
| odpovídatanswer; answer regularlyVerb | Verb |
| odtáhnoutpull away; tow awayVerb | Verb |
| odtamtudfrom thereAdverb | Adverb |
| odtudfrom hereAdverb | Adverb |
| odvážnýbrave; boldAdjective | Adjective |
| odvéstlead away; take awayVerb | Verb |
| odvézttake away by vehicle; drive awayVerb | Verb |
| ohlásitreport; announce; registerVerb | Verb |
| ohňostrojfireworks displayNoun | Noun |
| ohodnocenívaluationNoun | Noun |
| oholit seshave oneselfVerb | Verb |
| ochotawillingnessNoun | Noun |
| ochranaprotectionNoun | Noun |
| ochutnattaste; try food or drinkVerb | Verb |
| ochutnávattaste; sample repeatedlyVerb | Verb |
| ojetýused; worn (esp. car)Adjective | Adjective |
| okamžitěimmediatelyAdverb | Adverb |
| oknowindowNoun | Noun |
| okoeyeNoun | Noun |
| okolísurroundingsNoun | Noun |
| okopírovatcopyVerb | Verb |
| okresnídistrictAdjective | Adjective |
| okupaceoccupationNoun | Noun |
| okurkacucumberNoun | Noun |
| okurkovýcucumberAdjective | Adjective |
| olejoilNoun | Noun |
| olovoleadNoun | Noun |
| olympiádaOlympicsNoun | Noun |
| omáčkasauceNoun | Noun |
| omezenýlimited; restrictedAdjective | Adjective |
| omlouvat seapologise; apologizeVerb | Verb |
| omluvit seapologiseVerb | Verb |
| omylmistakeNoun | Noun |
| onhePronoun | Pronoun |
| onashePronoun | Pronoun |
| opačnýoppositeAdjective | Adjective |
| opakovatrepeatVerb | Verb |
| opalovánítanningNoun | Noun |
| opalovat sesuntanVerb | Verb |
| operaoperaNoun | Noun |
| operaceoperationNoun | Noun |