1
general::
Also, at that rate. 1. Progressing at this (or that) speed, as in At this rate we'll never finish in time. [Mid-1600s] 2. Under these circumstances, in that case. For example, At this rate they'll never settle their differences. [Late 1700s]
American Heritage Idioms
2
general::
Phrase(s): at this rate
at this speed; if things continue in the same way. (Usually of a pessimistic view.) • Hurry up! We’ll never get there at this rate. • At this rate, all the food will be gone before we get there.
McGrawhill's American Idioms And Phrasal Verbs