+0
3low
3: DEAD — used as a predicate adjective with lay <laid the enemy low>

3predicate
: completing the meaning of a copula <predicate adjective> <predicate noun>

copula
: something that connects: as a : the connecting link between subject and predicate of a proposition b : LINKING VERB

[All the definitions from M-W's Col. Dic.]

Questions:
1: Please explain the predicate adjective.
2: Do you find the above definition of copula satisfactory?
Comments  
Grass is a plant.

Grass is green.
Predicate noun.
Predicate adjective.
Copula.
Thank you, Huevos, for such a wonderful answer.

Best regards,
Jackson