Mismatched entity and/or field definitions
I got the above errors but with the node table. I am not sure if this is a safe thing to do but I executed the following MySQL command at the prompt:

ALTER TABLE node DROP INDEX node_field__uuid__value;


After that the entity updates executed without any problem.

For the author's problem I suppose you could adapt the command to:

ALTER TABLE taxonomy_term_data DROP INDEX taxonomy_term_field__uuid__value;


The key should be generated the next time you run that entity updates Drush command.