"is is was"how can you build a word out of this without any omission?

Answer 1

This is a tongue twister (the answer is in the third line):-

"An is is just a was that was
And thaat is very small....
And is is was so soon it almost wasn't is at all,
For is is only is until it is a was you see....
And as an is advances to remain an is can't be
'Cause if is is to stay an is it isn't is because
Another is is where is was and is is then a was."

Or try this riddle:- "what was is is and what is was was is is was is was is was what is was"

Answer 2

what is is (today) was yesterday.