op|er|a|tor

op|er|a|tor «OP uh _RAY tuhr», noun.

1. a person who operates: »

The operator of an automobile must have a license.

2. a skilled worker who operates a machine, telephone switchboard, telegraph, or other device: »

a telegraph or telephone operator. Operators taken off other machines say they “feel” the sensation of [the computer's] cosmic speed (Newsweek).

3. a person who runs a factory, mine, or other establishment or concern: »

The mine operators met with the striking workers.

4. U.S. Informal. a shrewd individual who maneuvers people and events for his own purposes: »

The musical stars Robert Preston, as a fast operator who is redeemed by contact with prairie honesty (New Yorker).

5. a person who speculates in stocks or a commodity.

6. a doctor who performs surgical operations; surgeon.

7. Mathematics. a symbol indicating or expressing an operation to be carried out.

8. the part of the operon that activates and regulates the structural genes; operator gene: »

According to a now classic hypothesis in genetics, there are two classes of genes. The first consists of structural genes that, through RNA, determine the sequence of the amino acids and thus the structure of protein. The second class of genes, called operators, control the first, turning them on and off to regulate gene expression. Working as a unit, a package of structural and operator genes is called an operon (Science News).