vehicle

a conveyance that transports people or objects

a medium for the expression or achievement of something; "his editorials provided a vehicle for his political views"; "a congregation is a vehicle of group identity"; "the play was just a vehicle to display her talents"

any substance that facilitates the use of a drug or pigment or other material that is mixed with it

any inanimate object (as a towel or money or clothing or dishes or books or toys etc.) that can transmit infectious agents from one person to another