helmet

helmet — noun

1. a hard, durable covering worn on the head to lower the chance of injury during a

1.nounB1
Definition

a hard, durable covering worn on the head to lower the chance of injury during activities such as cycling, construction work, or contact sports

Example

Bao always wears his helmet when he rides his bicycle to school.

collocation: wear a helmet

The building boss checked that every worker wore a hard helmet on site.

collocation: hard helmet (material type)

Common collocations
  • wear a helmet
  • put on a helmet
  • take off a helmet
  • cycling helmet
  • safety helmet
  • crash helmet
  • helmet strap
  • helmet visor
Synonyms
  • hard hat

    limited to construction and industrial use; not worn for cycling or sports

  • crash helmet

    specifically for high-speed protection such as motorcycle racing or car racing

  • headgear

    much broader term that includes hats, caps, and hair accessories — not limited to protective gear

Usage Note

The most common verbs with this sense are 'wear', 'put on', and 'take off'. A helmet can be described by its purpose (cycling helmet, safety helmet) or material (hard helmet, carbon-fibre helmet). In many places, wearing a helmet is required by law for motorcyclists and cyclists.

Common Mistakes

I forgot my safety hat at home.' (when you mean a bicycle helmet)
I forgot my helmet at home.
'Hard hat' or 'safety hat' is specific to construction; for cycling or sports, use 'helmet'.
He helmet his head before riding the bike.
He put on his helmet before riding the bike.
'Helmet' is a noun only; it is not used as a verb in standard English.

2. a metal head covering worn as part of a soldier's armour, especially in ancient

2.nounB2
Definition

a metal head covering worn as part of a soldier's armour, especially in ancient or medieval times, designed to protect against swords, arrows, and other weapons

Example

The knight's heavy metal helmet covered his entire face except for a narrow slit.

collocation: metal helmet

In the history museum, Anjali saw a bronze helmet worn by soldiers in ancient Greece.

Common collocations
  • knight's helmet
  • metal helmet
  • iron helmet
  • bronze helmet
  • helmet visor
  • plume on a helmet
  • helmet crest
Synonyms
  • headpiece

    a more general term for any head covering in armour, not necessarily made of metal

  • visor

    refers only to the movable front part of a helmet that protects the face, not the whole helmet

Usage Note

This sense appears mainly in historical, fantasy, or museum contexts. Unlike the modern safety-helmet sense, these helmets are usually made of metal and described by period or culture (Roman, samurai, Viking) or by design features (visor, crest, visor slit).

Common Mistakes

The soldier wore a metal helmet to keep his head dry in the rain.
The soldier wore a metal helmet to protect his head from swords and arrows.
This sense is about combat protection against weapons, not weather.

Word family

  • helmeted
    adjectiveC1

Synonym discussion

Sense: noun/1

Helmet, hard hat, crash helmet, and headgear all refer to things you wear on your head, but they are not interchangeable. Helmet is the broadest term — it covers everything from a bicycle helmet to a medieval knight's helmet. Hard hat is limited to the rigid head protection used on construction sites and in industrial workplaces; you would never call a cycling helmet a hard hat. Crash helmet refers specifically to the thick, heavy headgear worn by motorcycle racers or rally drivers, designed for high-speed impacts. Headgear is the widest category of all — it includes helmets, hats, caps, religious coverings, and even hairbands. So a hard hat is a type of helmet, but not all helmets are hard hats. For example: 'Every worker on the building site must wear a hard hat' (safety, not sports) and 'She bought a warm woollen headgear to wear under her cycling helmet in winter.'

helmet ↗hard hatcrash helmetheadgear

Common collocations

Nouns

  • visor
  • strap
  • liner
  • chin strap

Adverbs

Phrases

  • put on a helmet
  • take off a helmet
  • fasten a helmet
  • remove a helmet

Prepositions

  • with a helmet
  • without a helmet

Etymology

Proto-Indo-EuropeanProto-GermanicOld EnglishMiddle EnglishEnglish

Helmet comes from Middle English 'helmet', which was a smaller version of 'helm', an Old English word for a protective head covering. The '-et' ending originally meant 'little', so a helmet was literally a 'little helm' — a lighter headpiece compared to the full, heavy helms worn in medieval combat. 'Helm' itself traces back through Proto-Germanic '*helmaz' to the Proto-Indo-European root '*kel-', meaning 'to cover or conceal'. The same root gave us 'helm' (a steering mechanism — originally meaning 'that which covers/controls') and, through Latin, 'cell' (a covered room) and 'conceal'.