Look, expression, bearing

Estremeceu com o barulho da porta is a sentence English will render with « he gave a start », and the noun in that phrase is a fossil. « To start » began as a verb of the body, not of the clock: in Old English styrtan meant to leap up, and for centuries to start was to jump involuntarily — at a noise, at a touch, at bad news. The sense of beginning grew out of that by way of setting off with a sudden movement, and it has since swallowed the word so completely that « she started at the noise » now reads as literary or old. What survives of the older meaning is scattered about in fixed company: « to give a start », « to start back », « to wake with a start », and above all « startle », which carries the same root and means to make somebody do it. Estremecer has kept the whole of that ground, because it is built on tremere, to tremble, and has never had a second career as a verb of beginnings. So read it as the body moving first and the mind catching up.