Under a franchise arrangement, a person or company purchases the ability to run a local business under a larger company's brand. Depending on the franchise arrangement, the local party may have to meet certain standards established by the larger company and purchase products from the larger company as well.
Half-cock is when the position of the hammer is partially but not completely cocked.
Half-life of medication (a longer half-life will mean it takes much longer for the medication to completely clear from your body) The specific side effect to which you are referring. Some adverse events are not reversible (although this is rare). Others may take time to resolve themselves.