noscitur a sociis

Latin, meaning "it is known from its associates."

• (Latinate) IPA^(key): /nɒskiˈtuˑɹ ˌɑˑ ˌsɔkiːʔiˑs/
• (Received Pronunciation) IPA^(key): /ˌnəʊsɪtʊə ˈɑː ˌsəʊsiɪs/

noscitur a sociis

1. (law) A canon of construction under which the questionable meaning of a doubtful word can be derived from its association with other words.

   Foster v Diphwys Casson (1887) 18 QBD 428, involved a statute which stated that explosives taken into a mine must be in a "case or canister". Here the defendant used a cloth bag. The courts had to consider whether a cloth bag was within the definition. Under noscitur a sociis, it was held that the bag could not have been within the statutory definition, because parliament's intention was referring to a case or container of the same strength as a canister.

• ejusdem generis
• expressio unius est exclusio alterius