type Word = Cardinal;
Word is the “natural” unsigned integer type in GNU Pascal. On some platforms it is 32 bits wide and thus has a range of 0 .. 4294967295. It is the same as Cardinal, introduced for compatibility with other Pascal compilers.
There are lots of other integer types in GPC, see Integer Types.
Word is defined in Borland Pascal and Borland Delphi, where it is a 16-bit unsigned integer type.
program WordDemo; var a: Word; begin a := 42; WriteLn (a) end.
Cardinal, Integer Types, Subrange Types.