Metaphor

The thing in question, the subject itself, 
is the tenor. Tenor comes from the Latin 

tenere, meaning to hold or connect one 
thing to another; to make a continuance.

The vehicle is the element that helps
to make the leap from the grounded

image to the idea for comparison.
For instance, how the bird of hope

declines in its poorly kept cage;  
how even a snail is parched for want

of a rumor of water. How I wander the days,
listening for the sound of a door opening.