Possible to add a word count limit to a custom field?

I’m trying to figure out a way to limit the content of a custom field to only X number of words, if the content of the custom field is greater than X I’d like to display an ellipsis […] after the last allowed word where it cuts off.

Searching hasn’t produced much luck with limiting custom fields but I’m still digging through results. Would be extremely thankful if anyone could point me in the right direction or could offer any assistance.