What is the definition of "Keri"?
Rashi #1 (citing the Sifra) and Targum Yonasan: It means haphazardly (on and off). 1
Rashi #2 (citing Menachem ben S'ruk and Targum Onkelos): It means to refrain 2 from performing the Mitzvos.
Targum Onkelos: It means 'If you go with Me tough' (unyielding).
Rashi: As in Mishlei, 25:17 & 17:27.
Rashi, explaining Targum Onkelos: To harden their hearts to rebel against Hashem.
How can the Torah state "Sheva ke'Chatoseichem", and then list only six punishments?
Rashi (in Pasuk 22): This is because, based on the Pasuk in Ki Savo Devarim, 32:24 "ve'Shen Beheimos Ashalach bam", "Veshiklah eschem" incorporates both the teeth of wild beasts and of domesticated animals. 1
See also Sifsei Chachamim.