In British English, a fish slice is a kitchen tool with a wide flat blade with long holes in it, used for lifting and turning food while cooking. In American English, this is known as spatula.
It was originally a serving implement for fish, usually made of silver, antique examples of which commonly appear at auction. Fish slices were made of silver or Sheffield plate rather than steel to avoid the possibility of tainting the taste of the fish due a reaction between the fish and its lemon seasoning and the steel. After 1745 their outlines were usually fish shaped.
The term now refers to an implement used for turning fish and other foods when frying them, available in many materials such as stainless steel. In the US a fish slice is regarded as a type of spatula and may be called a turner.