fill up

verb

By · According to Wiktionary data (CC BY-SA) ·

"fill-up" is a 6-letter English headword indexed on PlainSpell.

The verdict

“fill up” is outside the top-ranked English vocabulary, used as a verb - the kind of word writers most often double-check.

Unranked
below top-frequency English
7
letters

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - To make (something) completely full.

Key facts for fill up
PropertyValue
Headwordfill up
LanguageEnglish
Part of speechVerb
Letters7
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Where “fill up” sits in English frequency

fill up falls outside the top-100,000 ranked English words, the long-tail zone of technical, archaic, or low-frequency vocabulary, exactly where readers second-guess spellings most.

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

Spelling & Dictionary Insight

The English entry for fill up is 7 letters long, classified as a verb. It sits outside the most-frequent rank tiers, which is often why uncommon words generate more spelling variants per reader. Wiktionary records 10 distinct senses for this headword, so context determines which meaning a reader should apply.

We couldn't generate a plausible misspelling set for fill up, and the word's spelling is regular enough that our generator found nothing worth flagging. It is not paired with a close-neighbour confusable in our dataset, which usually means its spelling is distinct enough that readers don't reach for a similar-looking word instead.

No documented word history exists for this headword, so its spelling is best read as a straightforward mapping from sound to letter. The correct English form is fill up, spelled F-I-L-L- -U-P.

Definition

  1. 1
    To make (something) completely full.
  2. 2
    To fill the tank of a vehicle with fuel.
  3. 3
    To become completely full.
  4. 4
    To become tearful as a result of strong emotion.
  5. 5
    To annoy, or displease, by taunting, or by excessive nagging.
  6. 6
    To satisfy the hunger of (someone).
  7. 7
    To satisfy one's hunger; to stop being hungry.
  8. 8
    To make a full house on the turn or the river.
  9. 9
    To fill in / fill out a form etc.
  10. 10
    To make complete, to bring to a full development.

This word in other languages

llenar(Español)remplir(Français)anfüllen(Deutsch)encher(Português)

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 "fill up"?
"fill up" is spelled F-I-L-L- -U-P.
What does "fill up" mean?
As a verb, "fill up" means: To make (something) completely full.
What language does "fill up" come from?
"fill up" is a English word. PlainSpell covers definitions, pronunciations, and spelling data across English, Spanish, Portuguese, French, and German.
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.

Using “fill up”

The practical upshot for anyone who landed here from a spell-check.

  • The one correct English spelling is F-I-L-L- -U-P - every other letter order is a misspelling in standard orthography.
  • Browse more English words and confusable pairs in the same reference. English words
Data Source

Wiktionary (via kaikki.org), licensed under CC BY-SA & GFDL. Word ordering uses an open word-frequency list; misspelling variants are generated by edit-distance from the correct headword.

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

Source: FrequencyWords open word-frequency list FrequencyWords open word-frequency list