/ ˌəʊvəˈtæks; NAmE ˌoʊvərˈt-/ verb [ vn ] overtax sb/sth / yourself
1.
to do more than you are able or want to do; to make sb/sth do more than they are able or want to do :
to overtax your strength
Take it easy. Don't overtax yourself.
2.
to make a person or an organization pay too much tax