1. A substance that renders another substance, or catalyst, active, or that accelerates a process or reaction.
2. The fragment, produced by chemical cleavage of a proactivator, that induces the enzymic activity of another substance.
3. An apparatus for making substances radioactive; e.g., neutron generator, cyclotron.
4. A removable type of myofunctional orthodontic appliance that acts as a passive transmitter of force, produced by the function of the activated muscles, to the teeth and alveolar process that are in contact with it.
catabolite gene activator
tissue plasminogen activator