Having forty winks and Nod off

Nod off and having forty winks are semantically related. in fall asleep topic. In some cases you can use "Nod off" instead a verb phrase "Having forty winks".

Nod off verb - Change from a waking to a sleeping state.

Having forty winks and nod off are semantically related. Sometimes you can replace phrase "Having forty winks" with "Nod off", this terms are similar.