Very joyful and content. Clams are dug at low tide, so a clam at high tide would be able to remain uncaught. Look at your sister out there! She's happy as a clam at high tide now that she's back in the starting lineup again. I know I'll be happy as a clam at high tide once I get this stupid cast off my leg.

To be in very good spirits. The phrase's origin is unknown, but it may refer to Australian boxer Larry Foley. I was as happy as Larry when I found out that I'd gotten an A on my hardest exam.

In very good spirits. The phrase's origin is unknown, but it may refer to Australian boxer Larry Foley. I was as happy as Larry when I found out that I'd gotten an A on my hardest exam.

Very happy; contented. I've been happy as the day is long ever since we moved to the countryside. Johnny's in a bit of a bad mood, but just give him a new toy to play with and he'll be as happy as the day is long.

Very joyful and content. Look at your sister out there! She's happy as a clam in butter sauce now that she's back in the starting lineup again. I know I'll be happy as a clam in butter sauce once I get this stupid cast off my leg.

slang One who drives excessively or dangerously fast in a car. The phrase is based on the expression "have a lead foot," meaning to have a tendency to speed when driving. The image is that of one's foot being made of lead, which is very heavy, and thus pushing down on the accelerator. I've always been a bit of a Larry Leadfoot when I get behind the wheel, so I've gotten my fair share of speeding tickets. Some Larry Leadfoot went flying past me on the interstate and nearly careered into a truck.