on board

prep

"on-board" is a 7-letter English headword indexed on PlainSpell.

The verdict

“on board” is uncommon English (outside the top frequency list), classed as a preposition. The kind of spelling people second-guess.

Unranked
below top-frequency English
8
letters

According to Wiktionary data (CC BY-SA, analyzed September 3, 2026) - On or in (a means of transportation).

Corpus desk

Index EN-on-board · on board · English

on board · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-LONG 8 letters
  • VOW-3 3 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "O" thin
  • PHOTO-UNK Peer pending

Read with this headword: Spelling guide for this pattern

Desk codes from Wiktionary headword shape, FrequencyWords rank tier, confusable-pair count, generated misspelling depth, letter-cohort book size, and photo-finish peer. Not a difficulty grade.

Key facts for on board
PropertyValue
Headwordon board
LanguageEnglish
Part of speechPreposition
Letters8
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “on board” in English

on boardranks outside the top 100,000 English headwords, in the long tail of specialist, archaic, or seldom-used vocabulary, exactly the territory where a reader stops mid-sentence to double-check spelling.

Beyond rank #100,000. Source: FrequencyWords open word-frequency list.

Rare enough to double-check

on board is uncommon English outside the top frequency list, classed as apreposition. Rarity is why readers land here mid-draft. Gloss: "On or in (a means of transportation).".

on board doesn't appear in our generated misspelling index, since its letter sequence doesn't invite the usual edit-distance slips. Our dataset records no confusable match here, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: Originally a literal reference to the wooden boards of the deck of a boat or ship. The correct English form is on board, spelled O-N- -B-O-A-R-D.

Definition

  1. 1
    On or in (a means of transportation).

Recorded use

Wiktionary examples

These source excerpts show how on board appears in context. They illustrate usage; the definition above remains the entry’s reference meaning.

  1. On board his boat were various firearms but not much food.
  2. Even when I am on board the plane, I can never feel secure that my luggage is, too.

Etymology

Originally a literal reference to the wooden boards of the deck of a boat or ship.

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "on board"?
"on board" is spelled O-N- -B-O-A-R-D.
What does "on board" mean?
As a preposition, "on board" means: On or in (a means of transportation).
What is the origin of the word "on board"?
Originally a literal reference to the wooden boards of the deck of a boat or ship. See the full etymology section above for more details.
Is PlainSpell free to use?
Yes, PlainSpell is a completely free word reference. You can look up definitions, pronunciations, confusable pairs, homophones, and spelling corrections across 5 languages without any sign-up or subscription.

Source: Wiktionary (via kaikki.org) Structured Wiktionary extract

Source: FrequencyWords open word-frequency list