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Main Entry: strange
Pronunciation: 'strAnj
Function: adjective

1a archaic : of, relating to, or characteristic of another country : FOREIGN b : not native to or naturally belonging in a place : of external origin, kind, or character
2 a : not before known, heard, or seen : UNFAMILIARb : exciting wonder or awe : EXTRAORDINARY
3 a : discouraging familiarities : RESERVED, DISTANTb : ILL AT EASE
4 : having the major characteristic of strangeness <strange quark> <strange particle>

Which definition of the word strange is used in the sentence below?

The scientist had never seen the strange bacteria before he observed it growing in the dish.