Riddle

I have a phrase
That's more than a phrase
When its meaning
Comes from me

It starts with "i"
And ends with "U"
Around a four-letter word
Ending in "E"

Revealing the first three
Would give it away
Since the "E"
Is silent already

So I give you this riddle
To hint at the secret
That I've been wanting to say
But am not ready.