trans·ac·ti·vate (trāns-āk'tə-vāt', trānz-) tr.v.
trans·ac·ti·vat·ed, trans·ac·ti·vat·ing, trans·ac·ti·vates To stimulate (a host cell) to replicate the genetic components of a virus. Used of a viral protein. trans'ac·ti·va'tion n., trans·ac'ti·va'tor n.