FYI, I see this fairly often when hitting Cmd-shift-dash to enter a nonbreaking hyphen (which I do quite a lot when typing standard manuscript format in Courier, as I use two nonbreaking hyphens to indicate an em dash).
It doesn't happen every time, but mabe as often as one time in three. CPU goes to 100%, cursor goes to beachball, and after a few seconds (if I don't get impatient and kill it first) Word crashes.
It's possible that it happens more often in Outline mode, and possible that it happens more often after a large (100-200 word) paste and before a save.
Crash report below (omitting the thread details, which I assume someone can look up from the UUIDs). Hope this helps reproduce it.
Microsoft Error Reporting log version: 2.0
Error Signature:
Exception: SIG_HANG_QUIT
Date/Time: 2015-10-02 20:55:12 +0000
Application Name: Microsoft Word
Application Bundle ID: com.microsoft.Word
Application Signature: MSWD
Application TimeStamp: 0x55f2d316
Application Version: 15.14.150911
Crashed Module Name: Microsoft Word
Crashed Module Version: 15.14.150911
Crashed Module Offset: 0x010c38d0
Blame Module Name: Microsoft Word
Blame Module Version: 15.14.150911
Blame Module TimeStamp: 0x55f2d316
Blame Module Offset: 0x00000000010c38d0
StachHash: 1acc
Application LCID: 1033
Extra app info: Reg=en Loc=0x0409
Crashed thread: 0
[thread details elided]
Microsoft Application Information:
Error Reporting UUID: 33D3EB4A-4AA0-4EE3-A746-5668277C54C8
ULS UUID: 2510FB0B-B7B1-425C-9B81-0BFCA65AEA3A
Time from launch: 0 hours, 10 minutes, 34 seconds
Total errors on this client: 9