unaware
Word family
Synonym discussion
Sense: adjective/1
All four words describe a lack of knowledge, but they differ in strength and connotation. 'Unaware' is the most neutral and general word — it simply means not knowing about something, without judgement. 'Oblivious' is much stronger and often implies the person should have noticed what was going on around them ('He was oblivious to the dirty looks he was getting'). 'Ignorant' can mean lacking specific knowledge ('I am ignorant of the details'), but it is also used more broadly to mean uneducated, which can feel insulting — use with care. 'Unconscious' describes a lack of awareness that is inside the person, often about their own behaviour or feelings ('She was unconscious of how loudly she was speaking'). For a neutral statement about not knowing a fact, 'unaware' is almost always the safest choice.
Common collocations
Etymology
The word 'unaware' was formed in English by adding the prefix 'un-' (meaning 'not') to 'aware'. 'Aware' comes from Old English 'gewær', meaning watchful or vigilant. The adverb 'unawares' appeared later in the 16th century, adding the adverbial '-s' ending (the same '-s' found in words like 'sideways' or 'needs' used as an adverb).