What is the word that means a query predicate can use an index
The word you're looking for is &quot;SARGable&quot;. From Wikipedia:

In relational databases, a condition (or predicate) in a query is said
to be sargable if the DBMS engine can take advantage of an index to
speed up the execution of the query. The term is derived from a
contraction of Search ARGument ABLE.