http://tree-tech.com/board/?topic=topic4&msg=323

Following up on this earlier thread I just happened to find a caption "First signs of imminent failure through continuous inclination of a slanted tree" accompanying a figure in an article:

Mattheck, Claus and Helgo Breloer, 1994. "Field Guide for Visual Tree asssessment (VTA)." Arboricultural Journal (UK). Vol. 18 pp. 1-23. Figure 15, p. 20.

The usage is not clearly defined and there might be a translation issue, but the related text seems to suggest it is intended to mean that the observed conditions indicate a high lilklihood of failure.