1) An alternative spelling of ‘crouch’ in the sense of cross.
2) A curved piece of timber, one of a roughly matched pair, or two sawn from one tree.
Together they formed a rough arch, and two pairs at a distance supported the ridge timber of a building. In the OED the evidence for this term is late and appears under the headwords crock, crook and cruck. The Yorkshire examples are therefore important: 1352 ‘Margery del Milne is amerced 6d for felling trees … 40d for selling 6 crokkes’, Holmfirth
1380 ‘will build anew one grange of 6 posts or of six crokkes’, Yeadon
1454 ‘laying great stones under the foot of the Crokk’, Airton
1509 bield … a house of vj crokkys, South Crosland. Frequent references continue through the sixteenth century: 1573 to find great tymber and all other woode needful for the buildynge of one house of thre pare of crockes of whyte woode, Kilnsey.