english
1
general::
Not to exaggerate, as in When the ring turned up in the lost and found, she was delighted, to say the least. This idiom was first recorded in 1809.
American Heritage Idioms
2
general::
Phrase(s): to say the least at the very least; without overemphasizing the subject; to put it mildly. • We were not at all pleased with her work—to say the least. • When they had an accident, they were upset to say the least.
McGrawhill's American Idioms And Phrasal Verbs