to experience a difficulty.

Our plans for Patty's surprise party hit a snag when we discovered she would be away that weekend.

• amour propre
• a mouth to feed
• a movable feast
• a mug's game
• a mummy's boy
• a mutual admiration society
• a mystery to
• a mystery to you
• an about-face
• an accident waiting to happen
• an ace in the hole
• an Achilles' heel
• an acid test
• a nail in the coffin of
• a nail in the coffin of something
• an Aladdin's cave
• an all-rounder
• an amber gambler
• an ambulance chaser
• a name to conjure with
• An apple a day keeps the doctor away.
• an arm and a leg
• a narrow escape
• an article of faith
• an awkward customer