Accession (&unr_;), n. [L. accessio, fr. accedere: cf. F. accession. See Accede.] 1. A coming to; the act of acceding and becoming joined; as, a king's accession to a confederacy.[1913 Webster]
2. Increase by something added; that which is added; augmentation from without; as, an accession of wealth or territory.[1913 Webster]
The only accession which the Roman empire received was the province of Britain.
3. (Law) (a) A mode of acquiring property, by which the owner of a corporeal substance which receives an addition by growth, or by labor, has a right to the part or thing added, or the improvement (provided the thing is not changed into a different species). Thus, the owner of a cow becomes the owner of her calf. (b) The act by which one power becomes party to engagements already in force between other powers. Kent.[1913 Webster]
4. The act of coming to or reaching a throne, an office, or dignity; as, the accession of the house of Stuart; -- applied especially to the epoch of a new dynasty.[1913 Webster]
5. (Med.) The invasion, approach, or commencement of a disease; a fit or paroxysm.[1913 Webster]
Syn. -- Increase; addition; augmentation; enlargement.[1913 Webster]