selector

noun7

1. •
   Someone or something which selects or chooses.

   • There is one selection for hot chocolate. All selectors are the push button type. — 1949
2. •
   An administrator responsible for selecting which players will play for a side.
3. •
   A matching expression in a stylesheet determining which elements in the markup are affected by a style.

   • The ID selector targets just one element per page, making it much more specific than a class selector that might target many. — 2007
4. •
   A disc jockey.

   • That's my sector, homosexual dissector / Come again, rewind selector — 2009
5. •
   (Australia, historical) A person who is entitled to choose a tract of Crown land to purchase.

   • Each selector in turn chose the particular allotment he wanted for his client, and so on till this important work was over. — 1887
6. •
   A pointer to a structure describing a segment of memory.

   • Phar Lap executables […] provide a protected-mode selector, 34h, that maps to the first megabyte of physical memory. — 1990
7. •
   (Internet, historical) A text string transmitted to a Gopher server, identifying the resource to be retrieved.

   • Gopher selector strings are more liberal in makeup than URLs and may contain any characters other than a tab, return, or linefeed. — 1996