copy/delete word under cursor in Vim
yw / byw

Assuming that the cursor is at the first character of the word simply do this in command mode:
     yw
y is for yank and w is for word.

Other ways of doing the same thing which are not as efficient:
     vey
the v starts visual select mode. e tells vim to move to end of word. y yanks or copies the word. to delete replace y with x.

if the cursor is somewhere in the middle of the word, add a b before the command as in:
     byw
or
     bvey
     
# http://www.littletechtips.com/2011/05/how-to-copydelete-word-under-cursor-in.html