Kerava and variants like Kärävä can be found more widely in place names in Tavastia and South Savonia as well. It is probably akin to käräjät (dialectal keräjät; for the consonantal variation, compare kataja ~ dialectal katava, pihlaja ~ dialectal pihlava), referring to places that were close to borders and thus to a place that required a public assembly to agree on who should own it. Less likely derived from kero(“throat”) as a reference to a narrow body of water.[1]
The external locative cases (adessive, allative and ablative) are used with this place name when referring to a location; for example, "in Kerava" is Keravalla.
^ Sirkka Paikkala, editor (2007), Suomalainen paikannimikirja [Book of Finnish Place names] (in Finnish), Helsinki: Karttakeskus, Kotimaisten kielten tutkimuskeskus, →ISBN