Word
firefly
Phoneticsfire·fly
US/ˈfaɪɝˌfɫaɪ/
UK/fˈaɪəflaɪ/
Countable noun
Definition
n. a small beetle that glows with a soft light in the dark. You usually see them flying around on warm summer nights.
n. a nocturnal beetle of the family Lampyridae, characterised by the use of bioluminescence to attract mates or prey.
Examples
“The children tried to catch a firefly in a glass jar.”
“As the sun set over the meadow, hundreds of fireflies began to blink in the tall grass.”
“The rhythmic flashing of the firefly is not merely decorative; it serves as a sophisticated species-specific signal used to locate potential mates in the dense evening foliage.”
Examples
simple
“The children tried to catch a firefly in a glass jar.”
contextual
“As the sun set over the meadow, hundreds of fireflies began to blink in the tall grass.”
complex
“The rhythmic flashing of the firefly is not merely decorative; it serves as a sophisticated species-specific signal used to locate potential mates in the dense evening foliage.”
Usage
Commonly referred to as a 'lightning bug' in certain regional dialects of American English.
Real-World Examples
“Experts say there are easy steps you can take to ensure your own yard has the soil conditions that fireflies need to survive.” Etymology
Endocentric compound of fire + fly, because the insects glow; whence also lightning bug. Compare glow fly, glowworm, and lanternfly.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Word family
VERB
NOUN
- Exam level
- CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.B2 FirstIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.5.5–6.5TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 4.0–4.572–94TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.785–944
- Frequency
- Occasional
- Level
- B2 · Upper Intermediate
- Updated
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