English Words: O

15,494 words · Page 17 of 310

observernoun

One who makes observations, monitors or takes notice.

observeressnoun

A female observer.

observerlessadj

Without observers.

observershipnoun

The office or work of an observer.

observestverb

second-person singular simple present indicative of observe

observethverb

third-person singular simple present indicative of observe

observingverb

present participle and gerund of observe

observinglyadv

Attentively, observantly.

obseshnoun

Obsession.

obsessverb

To be preoccupied with a single topic or emotion.

obsessedverb

simple past and past participle of obsess

obsessedlyadv

With an obsession.

obsessednessnoun

The quality of being obsessed; obsession.

obsesseenoun

One who is the object of someone's obsession.

obsessinglyadv

With an obsession; obsessively.

obsessionnoun

The quality of being obsessed.

obsessionaladj

Marked by obsession

obsessionalismnoun

obsessive behaviour

obsessionalitynoun

The quality of being obsessional.

obsessionallyadv

In an obsessional manner.

obsessionismnoun

Obsessiveness.

obsessionistnoun

A person who has an obsession; an obsessive.

obsessiveadj

Prone to cause obsession.

obsessive-compulsiveadj

Characterized by obsessions and compulsions, especially by the need to perform repetitive tasks.

obsessive-compulsivenessnoun

The state of being obsessive-compulsive.

obsessivelyadv

In an obsessive manner.

obsessivenessnoun

The characteristic of being obsessive.

obsessoidadj

Showing resemblance to obsessive-compulsive disorder.

obsessornoun

One who is obsessive about something.

obsidiannoun

A type of naturally occurring black glass produced by volcanoes.

obsidionaladj

Pertaining to a siege.

obsignverb

To seal; to confirm, as by a seal or stamp.

obsignateverb

To seal or ratify.

obsignationnoun

The act of sealing or ratifying.

obsignatoryadj

Ratifying; confirming by sealing.

obsolesceverb

To become obsolete.

obsolescencenoun

The state of being obsolete—no longer in use; gone into disuse; disused or neglected.

obsolescentadj

In the process of becoming obsolete, but not obsolete yet.

obsolescentlyadv

In an obsolescent manner.

obsoleteadj

No longer in use; gone into disuse; disused or neglected (often in favour of something newer).

obsoletelyadv

When out of date or no longer in use.

obsoletenessnoun

The quality or state of being obsolete or no longer in use.

obsoleternoun

Something which obsoletes something else.

obsoletionnoun

Obsolescence.

obsoletismnoun

A disused word or phrase; an archaism.

obsoletornoun

Something which obsoletes something else.

obsonatornoun

A caterer, a manciple.

Obstname

A surname from German.

obstaclenoun

Something that impedes, stands in the way of, or holds up progress, either physically or figuratively

obstacle coursenoun

A course with a series of physical challenges (running, climbing, swimming, etc.) to be performed sequentially.

Spelling & Dictionary Insight

The English alphabetical index for the letter O contains 15,494 headwords drawn from our Wiktionary-derived dictionary table. At 50 entries per page the browse splits into 310 pages, and you are currently viewing page 17. Every row above is a dictionary-backed entry with a canonical slug, and each links through to a full definition page with pronunciation, senses, etymology, and related-word data where available.

On this page 50 of 50 entries carry a part-of-speech tag and 50 carry at least one stored definition. Coverage varies across letters because Wiktionary volunteers build entries at different speeds for different parts of the alphabet, letters with common starting sounds (S, C, T, P) usually have the densest coverage, while less frequent starters (X, Q, Z) tend to have shorter but more specialised lists. PlainSpell surfaces whatever data is present and links back to the source when a definition is not yet recorded.

For readers using this index as a spelling reference, the guarantee is that every form you see on the list is a documented English headword, not a guess, not a derived inflection lacking a lemma row. If a word you expected to find is absent from the "O" list, it usually means the form exists only as an inflection of another lemma (e.g. a past participle stored under the infinitive) or the entry has not yet been imported from Wiktionary. Use the search bar or the misspelling lookup to resolve these cases.