An airfoil for an aircraft, the airfoil comprising a main wing having a leading edge and a high-lift body having a leading edge and a concavo-convex cross-section transversely to its leading edge such that a concave recess is defined by the high-lift body, which concave recess extends parallel to the leading edge of the high-lift body, wherein the high-lift body is coupled to the main wing at a recessed portion provided in the leading edge of the main wing such that the concave recess faces the main wing and wherein the high-lift body is selectively movable between a retracted position and a deployed position, wherein in the retracted position the leading edge of the main wing and the leading edge of the high-lift body form a continuous common leading edge, wherein the airfoil further comprises a sealing device having a first sealing element and a second sealing element arranged in the concave recess defined by the high-lift body, characterized in that the first sealing element and the second sealing element are plate-shaped, are rotatable about a common rotational axis relative the main wing and relative to each other and each have a respective side face, wherein both side faces extend perpendicular to the common rotational axis and parallel to each other, wherein the first sealing element abuts sectionally on the high-lift body, in that the sealing device is coupled to the high-lift body such that when the high-lift body is moved between the retracted position and the deployed position, the first sealing element and the second sealing element rotate relative to the main wing and relative to each other, such that when the first and the second sealing element (6, 7) are projected on a plane extending perpendicular to the common rotational axis, an overlap between the first and the second sealing element (6, 7) is smaller when the high-lift body is in the deployed position than when the high-lift body is in the retracted position, in that in the deployed position of the high-lift body at least part of a gap formed between the main wing and the high-lift body in a plane extending perpendicular to the common rotational axis is covered by the sealing device, and in that side face of the first sealing element and the side face of the second sealing element extend perpendicular to the common rotational axis when the high-lift body is in the retracted position and when the high-lift body is in the deployed position. a main wing having a leading edge and a high-lift body having a leading edge and a concavo-convex cross-section transversely to its leading edge such that a concave recess is defined by the high-lift body, which concave recess extends parallel to the leading edge of the high-lift body, wherein the high-lift body is coupled to the main wing at a recessed portion provided in the leading edge of the main wing such that the concave recess faces the main wing and wherein the high-lift body is selectively movable between a retracted position and a deployed position, wherein in the retracted position the leading edge of the main wing and the leading edge of the high-lift body form a continuous common leading edge, wherein the airfoil further comprises a sealing device having a first sealing element and a second sealing element arranged in the concave recess defined by the high-lift body, characterized in that the first sealing element and the second sealing element are plate-shaped, are rotatable about a common rotational axis relative the main wing and relative to each other and each have a respective side face, wherein both side faces extend perpendicular to the common rotational axis and parallel to each other, wherein the first sealing element abuts sectionally on the high-lift body, in that the sealing device is coupled to the high-lift body such that when the high-lift body is moved between the retracted position and the deployed position, the first sealing element and the second sealing element rotate relative to the main wing and relative to each other, such that when the first and the second sealing element (6, 7) are projected on a plane extending perpendicular to the common rotational axis, an overlap between the first and the second sealing element (6, 7) is smaller when the high-lift body is in the deployed position than when the high-lift body is in the retracted position, in that in the deployed position of the high-lift body at least part of a gap formed between the main wing and the high-lift body in a plane extending perpendicular to the common rotational axis is covered by the sealing device, and in that side face of the first sealing element and the side face of the second sealing element extend perpendicular to the common rotational axis when the high-lift body is in the retracted position and when the high-lift body is in the deployed position.