antibody: any of a large variety of proteins normally present in the body or produced in response to an antigen which it neutralizes, thus producing an immune response
protein: any of a large group of nitrogenous organic compounds that are essential constituents of living cells; consist of polymers of amino acids; essential in the diet of animals for growth and for repair of tissues; can be obtained from meat and eggs and milk and legumes
trip: a light or nimble tread