1) Burden and then some 2) Burden excessively 3) Cause strain to 4) Go heavy on the levy 5) Levy to excess 6) Make excessive demands on 7) Make great demands on 8) Put too much strain on 9) Soak the rich 10) Strain 11) Strain severely 12) Tax excessively 13) To make too great demands on 14) To overburden 1) Overload 
• (v. t.) To tax or to task too heavily.
O`ver·tax' transitive verb To tax or to task too heavily. 
[v] - tax excessively
to tax too heavily. · to make too great demands on.