grass up

verb

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

The verdict

“grass up” is uncommon English (outside the top frequency list), classed as a verb. 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) - To betray by informing on.

Corpus desk

Index EN-grass-up · grass up · English

grass up · unranked · 0 variants · 0 confusables

  • FREQ-UNRANKED Unranked
  • LEN-LONG 8 letters
  • VOW-2 2 vowels
  • CONFUS-0 No pairs
  • VAR-0 0 variants
  • BOOK-THIN "G" 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 grass up
PropertyValue
Headwordgrass up
LanguageEnglish
Part of speechVerb
Letters8
Misspellings tracked0
Confusable pairs0
SourceWiktionary (kaikki.org)

Long-tail rank of “grass up” in English

grass upsits beyond the 100,000 most-frequent English words, in the long tail of technical, archaic, or otherwise rare vocabulary where spelling doubt tends to strike hardest.

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

Rare enough to double-check

grass up is uncommon English outside the top frequency list, classed as averb. Rarity is why readers land here mid-draft. Gloss: "To betray by informing on.".

No generated misspelling entries exist for grass up in our index, since its letter pattern doesn't lend itself to common typo substitutions. No confusable counterpart is on file for this word, which typically means the spelling is too distinctive to be mistaken for another word.

Etymologically, the entry records: From grass (“informer”) + up. The correct English form is grass up, spelled G-R-A-S-S- -U-P.

Definition

  1. 1
    To betray by informing on.

Recorded use

Wiktionary example

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

  1. My sister grassed me up to the caretaker! She thought she was doing me a favour — by grassing me up she was sure he'd let me off.

Etymology

From grass (“informer”) + up.

Synonyms

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 "grass up"?
"grass up" is spelled G-R-A-S-S- -U-P.
What does "grass up" mean?
As a verb, "grass up" means: To betray by informing on.
What is the origin of the word "grass up"?
From grass (“informer”) + up. 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