1640s, "to demand too much of," from over- + tax (v.). Meaning "to levy taxes beyond what is equitable or reasonable, to tax heavily or excessively" is by 1823. Related: Overtaxed; overtaxing.
Entries linking to overtax
over-
word-forming element meaning variously "above; highest; across; higher in power or authority; too much; above normal; outer; beyond in time, too long," from Old English ofer (from PIE root *uper "over"). Over and its Germanic relations were widely used as prefixes, and sometimes could be used with negative force. This is rare in Modern English, but compare Gothic ufarmunnon "to forget," ufar-swaran "to swear falsely;" Old English ofercræft "fraud."
In some of its uses, moreover, over is a movable element, which can be prefixed at will to almost any verb or adjective of suitable sense, as freely as an adjective can be placed before a substantive or an adverb before an adjective. [OED]
Among the old words not now existing are Old English oferlufu (Middle English oferlufe), literally "over-love," hence "excessive or immoderate love." Over- in Middle English also could carry a sense of "too little, below normal," as in over-lyght "of too little weight" (c. 1400), overlitel "too small" (mid-14c.), oversmall (mid-13c.), overshort, etc.
tax v.
c. 1300, "impose a tax on," from Old French taxer "impose a tax" (13c.) and directly from Latin taxare "evaluate, estimate, assess, handle," also "censure, charge," probably a frequentative form of tangere "to touch," from PIE root *tag- "to touch, handle." Sense of "to burden, put a strain on" first recorded early 14c.; that of "censure, reprove" is from 1560s. Its use in Luke ii for Greek apographein "to enter on a list, enroll" is due to Tyndale. Related: Taxed; taxing.