1) The outer wood on a tree through which sap was still circulating.
Woodworkers in guilds were forbidden to use sap wood: the craft ordinances stated that their work had to be honestly done sauz [sic] ascun sappe, York
1629 If any joiner, carpenter or wright … find stuff himself he must not put in any sappie or unseasonable wood, Beverley. Moreover, felling trees had to be done at the right time of the year: 1580 to fell … in the wyntre season or out of sapp tyme, Thurstonland. Note: 1795 ten bluecoat boys with branches of plane or sap tree, Ripon.