bulb

/ˈbʌlb/

//ˈbʌlb// noun

"bulb" is a 4-letter English headword indexed on PlainSpell.

The verdict

“bulb” is a moderately-common English word, ranked #11,846 in English word frequency and used as a noun.

#11,846
frequency rank, English
4
letters
6
tracked misspellings
20
confusable pairs

According to Wiktionary data (CC BY-SA, analyzed May 6, 2026) - The bulb-shaped underground portion of a plant such as a tulip, consisting of a shortened stem and many fleshy scale leaves, from which the rest of the plant may be regrown.

Visual similarity to commonly confused words

How many letter changes separate each confused pair (Levenshtein distance, normalized).

bulb vs but
50% similar
bulb vs buy
50% similar
bulb vs bus
50% similar

Source: PlainSpell confusable corpus (Wiktionary, CC BY-SA).

Key facts for bulb
PropertyValue
Headwordbulb
LanguageEnglish
Part of speechNoun
IPA/ˈbʌlb/
Letters4
Frequency rank#11,846
Misspellings tracked6
Confusable pairs20
SourceWiktionary (kaikki.org)

Where “bulb” sits in English frequency

Every-word frequency runs from the handful of words we use constantly (left) to the long tail used once in a blue moon (right). bulb lands here:

#1#100#1K#10K#100K
← used constantlyrarely used →

Scale is logarithmic (each tick is 10× rarer). Source: FrequencyWords open word-frequency list.

Spelling & Dictionary Insight

The English entry for bulb is 4 letters long, classified as a noun, and transcribed in the International Phonetic Alphabet as /ˈbʌlb/. Corpus data places it at rank #11,846 in overall English word frequency, marking it as uncommon enough that many writers pause before typing it. Wiktionary records 6 distinct senses for this headword, so context determines which meaning a reader should apply.

Our generated misspelling index lists 6 likely wrong-spelling variants for bulb, with forms such as "bbulb", "blub", and "bubl". Every one of these variants traces to a single-character edit -- an added or dropped letter, a swapped consonant, or a vowel swap -- the kind of slip a spell-checker is built to catch. It also participates in 20 confusable-pair relationships, "but", "buy", "bus", and more, since the words sound or look close enough that writers reach for the wrong one mid-sentence.

Etymologically, the entry records: Etymology tree Ancient Greek βολβός (bolbós)bor. Latin bulbusder. English bulb Inherited from Middle English bulb, bolbe, from Latin bulbus (“bulb, onion”), from Ancient Greek βολβός (bolbós, “plant with round swelling on underground stem”). The correct English form is bulb, spelled B-U-L-B.

Definition

  1. 1
    The bulb-shaped underground portion of a plant such as a tulip, consisting of a shortened stem and many fleshy scale leaves, from which the rest of the plant may be regrown.
  2. 2
    The medulla oblongata.
  3. 3
    Any solid object rounded at one end and tapering on the other, possibly attached to a larger object at the tapered end.
  4. 4
    Any solid object rounded at one end and tapering on the other, possibly attached to a larger object at the tapered end.
  5. 5
    A bulbous protuberance at the forefoot of certain vessels to reduce turbulence.
  6. 6
    An onion.

Etymology

Etymology tree Ancient Greek βολβός (bolbós)bor. Latin bulbusder. English bulb Inherited from Middle English bulb, bolbe, from Latin bulbus (“bulb, onion”), from Ancient Greek βολβός (bolbós, “plant with round swelling on underground stem”).

This word in other languages

Common misspellings

Also misspelled as: bbulb,blub,bubl,bulbb,bullb,ublb

Misspelling Pattern Breakdown

How far each generated variant is from the correct spelling of bulb - measured in single-character edits (insert, delete, or substitute a letter). Larger bars are easier to catch; one-edit slips are the sneakiest.

bbulb1blub2bubl2bulbb1bullb1ublb2
Edit distance from "bulb"

Definitions, pronunciation, and etymology for this entry are drawn from Wiktionary via the kaikki.org structured extract (CC BY-SA); frequency ordering uses the FrequencyWords open word-frequency list (2018 English corpus, MIT). See the methodology for how each field is sourced and updated.

Frequently Asked Questions

How do you spell "bulb"?
"bulb" is spelled B-U-L-B. The IPA pronunciation is /ˈbʌlb/.
What does "bulb" mean?
As a noun, "bulb" means: The bulb-shaped underground portion of a plant such as a tulip, consisting of a shortened stem and many fleshy scale leaves, from which the rest of the plant may be regrown.
What words are commonly confused with "bulb"?
"bulb" is commonly confused with "but", "buy", "bus". These words look or sound similar but have different meanings. PlainSpell provides detailed comparisons for each pair.
How do you pronounce "bulb"?
The IPA (International Phonetic Alphabet) transcription for "bulb" is /ˈbʌlb/. Click the speaker icon on the pronunciation badge above to hear it spoken aloud where audio is available.
What is the origin of the word "bulb"?
Etymology tree Ancient Greek βολβός (bolbós)bor. Latin bulbusder. English bulb Inherited from Middle English bulb, bolbe, from Latin bulbus (“bulb, onion”), from Ancient Greek βολβός (bolbós, “plant with round swelling on underground stem”). 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.

Using “bulb”

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

  • The one correct English spelling is B-U-L-B - every other letter order is a misspelling in standard orthography.
  • Say it as /ˈbʌlb/ (IPA); tap the speaker on the pronunciation badge to hear it where audio exists.
  • Don't mix it up with “but” - see the side-by-side comparison. bulb vs but
  • 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