We have put together a list of words that are similar to BOUNDARY.

21 Alternative Words Similar to boundary

1 Bound Noun      Synonym Words Like Bound
2 Bounds Noun      Synonym Words Like Bounds
3 Edge Noun      Synonym Words Like Edge
4 Limit Noun      Synonym Words Like Limit
5 Extent Noun      Synonym Words Like Extent
6 Extremity Noun      Synonym Words Like Extremity
7 Line Noun      Synonym Words Like Line
8 Periphery Noun      Hyponym
9 Margin Noun      Hyponym Words Like Margin
10 Border Noun      Hyponym Words Like Border
11 Fringe Noun      Hyponym
12 Thalweg Noun      Hyponym
13 Utmost Noun      Hyponym Words Like Utmost
14 Surface Noun      Hyponym Words Like Surface
15 Outline Noun      Hyponym Words Like Outline
16 Hairline Noun      Hyponym Words Like Hairline
17 End Noun      Hyponym Words Like End
18 Heliopause Noun      Hyponym
19 Bourn Noun      Hyponym Words Like Bourn
20 Demarcation Noun      Hyponym Words Like Demarcation
21 Bourne Noun      Hyponym Words Like Bourne

1 examples of boundary

1 to the limit of his ability

10 definitions of boundary

1 That which indicates or fixes a limit or extent, or marks a bound, as of a territory; a bounding or separating line; a real or imaginary limit.
2 a line determining the limits of an area
3 the greatest possible degree of something
4 the line or plane indicating the limit or extent of something
5 Something that indicates a border or limit.
6 The border or limit so indicated.
7 That which serves to indicate the bounds or limits of anything; hence, a limiting or bounding line; a bound: as, the horizon is the boundary of vision; the northern boundary of the United States.
8 The dividing line or location between two areas.
9 An edge or line marking an edge of the playing field.
10 An event whereby the ball is struck and either touches or passes over a boundary (with or without bouncing), usually resulting in an award of 4 (a four) or 6 (a six) runs respectively for the batting team.
We get our data from many different dictionaries across the web:
Wordnik, Wiktionary, Century, American Heritage, Gcide