A participle is a verbal adjective (e.g. eating, going, running). It has properties of a verb in that it expresses aspect and voice. It has properties of an adjective in that it expresses case, gender and number.
καὶ ἀνακειμένων αὐτῶν καὶ ἐσθιόντων ὁ Ἰησοῦς εἶπεν Ἀμὴν λέγω ὑμῖν ὅτι εἷς ἐξ ὑμῶν παραδώσει με ὁ ἐσθίων μετ᾽ ἐμοῦ. (Mrk 14:18)
And as they were reclining and eating [verbal usage], Jesus said, “Truly I say to you that one of you will betray me, the one eating [nominal usage] with me.