Jam

A sweet mixture of fruit boiled with sugar and allowed to congeal. Often spread on bread or toast or used in jam tarts.

A difficult situation.

Blockage, congestion.

"A traffic jam caused us to miss the game's first period."

An informal, impromptu performance or rehearsal.

To get something stuck in a confined space.

"Her poor little baby toe got jammed in the door."

To brusquely force something into a space; cram, squeeze.

"The rush-hour train was jammed with commuters."

To cause congestion or blockage. Often used with "up"

"A single accident can jam the roads for hours."

To block or confuse a broadcast signal.