Definify.com
Webster 1913 Edition
Series
Se′ries
,Noun.
 1. 
A number of things or events standing or succeeding in order, and connected by a like relation; sequence; order; course; a succession of things; 
as, a continuous 
. series 
of calamitous eventsDuring some years his life a 
series 
of triumphs. Macaulay.
2. 
(Biol.) 
Any comprehensive group of animals or plants including several subordinate related groups. 
☞ Sometimes a series includes several classes; sometimes only orders or families; in other cases only species. 
4. 
(Math.) 
An indefinite number of terms succeeding one another, each of which is derived from one or more of the preceding by a fixed law, called the law of the series; 
as, an arithmetical 
. series
; a geometrical series
Webster 1828 Edition
Series
SE'RIES
,Noun.
             1. A continued succession in the things of the same order, and bearing the same relation to each other; as a series of kings; a series of successors.
           2. Sequence; order; course; succession of things; as a series of calamitous events.
           3. In natural history, an order or subdivision of some class of natural bodies.
           4. In arithmetic and algebra, a number of terms in succession, increasing or diminishing in a certain ratio; as arithmetical series and geometrical series. [See Progression.]