harmless

harmless — adjective

1. not harmful or dangerous; unlikely to hurt anyone, damage anything, or upset peo

1.adjectiveB1
Definition

not harmful or dangerous; unlikely to hurt anyone, damage anything, or upset people

Example

Most people find the dog scary, but he is harmless and just wants to play.

The snake that Omar found in the garden is a harmless type that eats insects.

harmless [type / species / kind] — describing animals

Common collocations
  • harmless to [humans / pets / the environment]
  • completely harmless
  • perfectly harmless
  • harmless fun
  • harmless joke
  • harmless remark
  • harmless species
  • harmless creature
  • harmless substance
Synonyms
  • safe

    broader meaning — can refer to being protected from danger, not just not causing it ('a safe neighbourhood')

  • innocuous

    more formal; typically describes remarks, habits, or substances that seem unimportant or unlikely to offend ('an innocuous comment')

  • non-toxic

    restricted to substances that are not poisonous ('non-toxic glue')

  • benign

    formal; used especially in medical contexts ('a benign tumour') or to describe a gentle person or thing

Antonyms
  • harmful

    direct opposite — causing or likely to cause harm

  • dangerous

    broader opposite — likely to cause injury or risk

  • toxic

    restricted to poisonous or chemically harmful substances

Grammar Patterns

a harmless [noun]

be harmless to [noun]

keep + [noun] + harmless

Usage Note

Commonly used to reassure someone that a person, animal, object, or remark is not a threat. Often followed by 'to' to specify who or what is not at risk (e.g. harmless to humans, harmless to the environment).

Common Mistakes

This snake is unharmed.' (when meaning it won't hurt you).
This snake is harmless.
'unharmed' means not injured oneself; 'harmless' means not causing injury to others.
This chemical is harmless for pets.
This chemical is harmless to pets.
the correct preposition after 'harmless' is 'to', not 'for'.

Word family

  • harm
    nounA2
  • harm
    verbB1
  • harmful
    adjectiveB1
  • harmlessly
    adverbB2
  • unharmed
    adjectiveB2

Synonym discussion

Sense: adjective/1

Harmless is the most general word for something that will not cause injury, damage, or offence. Safe is broader — it can mean either 'not likely to cause harm' or 'protected from harm' (e.g. 'Keep your money in a safe place'). Innocuous is more formal and often describes remarks, habits, or substances that seem unimportant or unlikely to cause offence ('an innocuous comment about the weather'). Non-toxic refers specifically to substances that are not poisonous ('non-toxic paint for children's toys'). Benign is formal and appears mostly in medical contexts for growths that are not cancerous, or to describe a kind, gentle nature. While harmless can describe people, animals, actions, remarks, and substances, safe is less common for describing a person's intent, and innocuous is rarely used for animals.

safeinnocuousnon-toxicbenign

Common collocations

Nouns

  • fun
  • joke
  • remark
  • prank
  • species
  • creature
  • insect
  • substance
  • chemical
  • activity

Adverbs

  • completely
  • perfectly
  • quite
  • relatively
  • seemingly
  • entirely

Phrases

  • harmless to humans
  • harmless to pets
  • harmless to the environment

Prepositions

  • to

Etymology

Old EnglishEnglish

Harmless comes from Old English 'hearmlēas', made up of 'hearm' (hurt, injury, pain) and '-lēas' (without). The word originally meant 'without harm' or 'uninjured' — describing someone who had not been hurt. By the late 1300s, the meaning had shifted to its modern sense: 'not causing harm to others.'