unfamiliar

unfamiliar — adjective

1. not known or recognized because you have never seen, met, or encountered it befo

1.adjectiveB1
Definition

not known or recognized because you have never seen, met, or encountered it before — for example, a face you do not recognize, a street you have never walked down, or a custom you have not come across.

Example

The librarian saw an unfamiliar face at the door and asked if she could help.

attributive: an unfamiliar face

Yara felt lost in the unfamiliar streets of the old city.

Common collocations
  • unfamiliar face
  • unfamiliar territory
  • unfamiliar surroundings
  • unfamiliar place
  • unfamiliar voice
  • unfamiliar name
  • unfamiliar language
  • unfamiliar concept
Synonyms
  • strange

    adds a feeling of oddness or unease that 'unfamiliar' does not necessarily carry

  • unknown

    suggests something has never been discovered or learned, often with a sense of mystery

  • foreign

    typically means from another country; metaphorically, anything alien to one's experience

Antonyms
  • familiar

    the direct opposite — known because seen or experienced before

  • known

    recognized or identified from previous experience

Grammar Patterns

unfamiliar + noun

unfamiliar to + person

Usage Note

Attributive before a noun ('an unfamiliar face') and predicative with 'to' ('the face was unfamiliar to me') are both natural in English. The subject of the sentence is the thing not known — not the person.

Common Mistakes

I am unfamiliar to this software.
I am unfamiliar with this software.
'unfamiliar to' means the software does not know you; use 'unfamiliar with' when you are the one lacking knowledge.

2. having no knowledge, skill, or experience of a particular subject, activity, or

2.adjectiveB1
Definition

having no knowledge, skill, or experience of a particular subject, activity, or situation — for example, not knowing how to use a piece of software, never having studied a topic, or being new to a role or environment.

Example

Reuben was unfamiliar with the software, so he asked a colleague for help.

unfamiliar with [something]

Many new students are unfamiliar with the campus rules during their first week.

Common collocations
  • unfamiliar with the rules
  • unfamiliar with the process
  • unfamiliar with the concept
  • unfamiliar with the system
  • completely unfamiliar with
  • totally unfamiliar with
Synonyms
  • new to

    less formal and suggests recentness rather than simple lack of knowledge — 'I am new to this software' implies you just started using it

  • unacquainted with

    more formal and less common in everyday speech — 'unacquainted with the details'

  • ignorant of

    stronger and often negative in tone, suggesting a failure to know something one should know

Antonyms

Grammar Patterns

be unfamiliar with + noun phrase

Usage Note

Always used predicatively after a linking verb (be, feel, seem) with the preposition 'with'. The subject is the person who lacks knowledge, and the topic they do not know follows 'with'. Never used attributively before a noun — compare an unfamiliar topic (sense 1, the topic is not known to anyone in general) with I am unfamiliar with the topic (sense 2, I specifically lack knowledge of it).

Common Mistakes

I am unfamiliar to this process.
I am unfamiliar with this process.
'unfamiliar to' reverses the relationship; the thing is unfamiliar to the person, not the person to the thing.
He is an unfamiliar worker with the system.
He is unfamiliar with the system.
'unfamiliar' cannot be used attributively in this sense.

Word family

  • unfamiliarity
    nounC1
  • familiar
    adjectiveA2
  • familiarity
    nounB2

Synonym discussion

Sense: adjective/1

Something unfamiliar is simply not known to you — you have never seen, met, or encountered it before. Strange adds a layer of unease or oddness: an unfamiliar place may be neutral, but a strange place feels unsettling. Unknown suggests something has never been discovered or learned, often with mystery (unknown territory). Foreign typically means from another country, but can metaphorically describe anything alien to your experience (the whole idea was foreign to him). Novel (C1) emphasises newness and originality rather than lack of familiarity — a novel approach is simply new and interesting, not confusing. For example: 'The system felt unfamiliar at first, but not strange.' / 'She was travelling in foreign lands where the customs were completely unfamiliar.' / 'The concept was so novel that even experts found it original.'

strange ↗unknown ↗foreign ↗novel ↗

Common collocations

Nouns

Adverbs

Phrases

  • unfamiliar territory

Prepositions

Etymology

Old English (un-)Latin (familiaris)English

Formed by adding the prefix 'un-' (meaning 'not', from Old English 'un-') to the adjective 'familiar', which comes from Latin 'familiaris' meaning 'of a household' or 'intimate'. The Latin root 'familia' means 'family' or 'household', so the literal sense is 'not of the family' — someone or something not known well enough to be considered part of one's inner circle. First recorded in English in the late 1500s.