/
prəˈmɪskjʊəs/
adj.
  - having or characterized by many transient sexual relationships.
 - indiscriminate or unselective.
 
Derivative
- promiscuity
  
/prɒmɪˈskjuːɪti/
 n.  - promiscuously adv.
  - promiscuousness n.
 
Etymology
C17: from L. promiscuus ‘indiscriminate’ (based on miscere ‘to mix’) + -ous.