Associative

Adjective

1. Pertaining to, resulting from, or characterised by association; capable of associating; tending to associate or unite.
2. Such that, for any operands a , b {\displaystyle a,b} and c {\displaystyle c} , ( a ∗<!-- ∗ --> b ) ∗<!-- ∗ --> c = a ∗<!-- ∗ --> ( b ∗<!-- ∗ --> c ) {\displaystyle (a*b)*c=a*(b*c)} ; whose multiplication operation is associative.
3. Addressable by a key more complex than an integer index.

   "AWK's associative arrays may be indexed by strings."