Field Word Boundary is a module that extends the settings for the Trimmed and Summary or trimmed formatters for long text fields.
The normal trim behavior will trim the text to a maximum length, by it's nearest sentence or paragraph boundary. This module will allow us to trim by the nearest word boundary instead, and will add an optional ellipsis.
If you're familiar with Views, you've probably used this settings in Views if you've printed a text field.
Since the formatter settings isn't alterable by core, this module depends on the Field formatter settings module.
If you don't want to use the Field formatter settings module, you should take a look at Smart Trim. This module pretty much accomplish the same thing, but instead of altering the existing formatters, you'll get a new one.
Module sponsored by Odd Hill