an appropriate or common activity.

When business is bad, cost-cutting is the order of the day.

Sadly, cheating seems to be the order of the day.

• in your right mind
• in your sights
• in your stockinged feet
• in your stocking feet
• in your wisdom
• I plead the Fifth
• I plead the Fifth Amendment
• I rest my case.
• I rest my case
• iron out
• iron out something
• iron out the kinks
• irons in the fire
• irregardless of
• irregardless of something
• is all need
• is all you need
• is anyone's guess
• is at disposal
• is at your disposal
• is bag
• is beyond me
• I shudder to think
• is in business
• is not a bed of roses