Protract comes from Latin protractus, past participle of protrahere ('to draw forth, lengthen'), from pro- ('forth') + trahere ('to draw, drag'). The historical chain includes Latin protrahere, Latin trahere, and Proto-Indo-European *tragʰ-. The quoted older senses, "to draw forth, lengthen", "forth", and "to draw, drag", supply the semantic anchors for protract. The formation is best read as compound, participial, and borrowed: the word protract carries its older form-history into a compact English lexical shape. In present English it is used as a verb, "to prolong or lengthen in duration". English derivatives include protraction, protractor, and protracted; related English forms include tractor, extract, retract, and abstract. The result is a verb whose etymology preserves both the older form and the later English specialization.