4. filthiness--obscenity in act or gesture.
      foolish talking--the talk of fools, which is folly and sin together. The Greek of it, and of "filthiness," occurs nowhere else in the New Testament.
      nor--rather, "or" (compare Eph 5:3).
      jesting--Greek, "eutrapelia"; found nowhere else in the New Testament: implying strictly that versatility which turns about and adapts itself, without regard to principle, to the shifting circumstances of the moment, and to the varying moods of those with whom it may deal. Not scurrile buffoonery, but refined "persiflage" and "badinage," for which Ephesus was famed [PLAUTUS, A Boastful Soldier, 3.1,42-52], and which, so far from being censured, was and is thought by the world a pleasant accomplishment. In Col 3:8, "filthy communication" refers to the foulness; "foolish talking," to the folly; "jesting," to the false refinement (and trifling witticism [TITTMANN]) Of discourse unseasoned with the salt of grace [TRENCH].
      not convenient--"unseemly"; not such "as become saints" (Eph 5:3).
      rather giving of thanks--a happy play on sounds in Greek, "eucharistia" contrasted with "eutrapelia"; refined "jesting" and subtle humor sometimes offend the tender feelings of grace; "giving of thanks" gives that real cheerfulness of spirit to believers which the worldly try to get from "jesting" (Eph 5:19, 20; Jas 5:13).

JFB.