speaking

a. 1. Uttering speech; used for conveying speech; as, man is a speaking animal; a speaking tube. [ 1913 Webster ]

2. Seeming to be capable of speech; hence, lifelike; as, a speaking likeness. [ 1913 Webster ]

A speaking acquaintance, a slight acquaintance with a person, or one which merely permits the exchange of salutations and remarks on indifferent subjects. --
Speaking trumpet, an instrument somewhat resembling a trumpet, by which the sound of the human voice may be so intensified as to be conveyed to a great distance. --
Speaking tube, a tube for conveying speech, especially from one room to another at a distance. --
To be on speaking terms, to be slightly acquainted. [ 1913 Webster ]