A waste-disposal device comprising: a structure having an opening at a top end and supporting a bag opened at the opening of the structure, with a closed end of the bag being below the opening; a lid assembly mounted to the structure and having a lid pivoting to close/open access to the opening; and a jaw mechanism comprising: a single pair of jaws with at least one of the jaws movingly connected to the structure below the opening to move between a clamped position in which the jaws concurrently close off a portion of the bag passing therebetween, and an opened position in which the jaws are separated to allow waste to reach the closed end of the bag under the single pair of jaws; an actuation link movingly connected to the structure and in a guide and follower engagement (45, 67) with the single pair of jaws to cause a movement of at least one of the jaws between the clamped position and the opened position as a result of movement of the actuation link relative to the structure, the actuation link contacting the lid for moving concurrently with the lid; at least one biasing element biasing the actuation link; characterized in that said least one biasing element is biasing the actuation link upwardly to raise the lid; and the jaw mechanism further comprises a retaining mechanism (34, 35) to hold the lid closed against a biasing pressure of the actuation link when the lid is pushed downwardly to close the access to the opening. a structure having an opening at a top end and supporting a bag opened at the opening of the structure, with a closed end of the bag being below the opening; a lid assembly mounted to the structure and having a lid pivoting to close/open access to the opening; and a jaw mechanism comprising: a single pair of jaws with at least one of the jaws movingly connected to the structure below the opening to move between a clamped position in which the jaws concurrently close off a portion of the bag passing therebetween, and an opened position in which the jaws are separated to allow waste to reach the closed end of the bag under the single pair of jaws; an actuation link movingly connected to the structure and in a guide and follower engagement (45, 67) with the single pair of jaws to cause a movement of at least one of the jaws between the clamped position and the opened position as a result of movement of the actuation link relative to the structure, the actuation link contacting the lid for moving concurrently with the lid; at least one biasing element biasing the actuation link; characterized in that said least one biasing element is biasing the actuation link upwardly to raise the lid; and the jaw mechanism further comprises a retaining mechanism (34, 35) to hold the lid closed against a biasing pressure of the actuation link when the lid is pushed downwardly to close the access to the opening. a single pair of jaws with at least one of the jaws movingly connected to the structure below the opening to move between a clamped position in which the jaws concurrently close off a portion of the bag passing therebetween, and an opened position in which the jaws are separated to allow waste to reach the closed end of the bag under the single pair of jaws; an actuation link movingly connected to the structure and in a guide and follower engagement (45, 67) with the single pair of jaws to cause a movement of at least one of the jaws between the clamped position and the opened position as a result of movement of the actuation link relative to the structure, the actuation link contacting the lid for moving concurrently with the lid; at least one biasing element biasing the actuation link; characterized in that said least one biasing element is biasing the actuation link upwardly to raise the lid; and the jaw mechanism further comprises a retaining mechanism (34, 35) to hold the lid closed against a biasing pressure of the actuation link when the lid is pushed downwardly to close the access to the opening.