pinch out verb 4noun 1forms 5 verb4 •To remove the shoots of a plant. •the leading shoot in order to encourage a bushy habit •a plant's side shoots •For a distinct body of rock between underlying and overlying strata, to thin out and come to an end, so that the strata above come to lie on the strata below. noun1 •A volume of rock or oil trapped or isolated between strata that have pinched it out. formspinched out · pinching out · pinches out · pinch outs · pinch-outs