let off steam

[let off steam] or [blow off steam] {v. phr.} 1. To let or makesteam escape; send out steam.

The janitor let off some steambecause the pressure was too high.

2. {informal} To get rid ofphysical energy or strong feeling through activity; talk or be veryactive physically after forced quiet.

After the long ride on thebus, the children let off steam with a race to the lake.

When therain stopped, the boys let off steam with a ball game.

Bill'smother was very angry when he was late in coming home, and let offsteam by walking around and around.

Bill had to take his foreman'srough criticisms all day and he would blow off steam at home byscolding the children.

Compare: BLOW ONE'S TOP, LET GO(6).