a cast-iron promise or arrangement is one that can be trusted completely.

No new business comes with a cast-iron guarantee of success. (always before noun)

• eat up
• eat words
• eat you alive
• eat your heart out
• eat your heart out!
• eat your words
• eat you up
• ebb and flow
• ebb and flow of
• ebb and flow of something
• effing and blinding
• either feast or famine
• either way
• elbow grease
• elbow room
• elders and betters
• elevator music
• eleventh-hour
• empty nest syndrome
• Empty vessels make most noise.
• Empty vessels make most sound.
• Empty vessels make the most noise.
• Empty vessels make the most sound.
• end it all
• end justifies the means.