A board foot is one foot long, one foot wide and one inch in thickness. Checking the Waste Mary Huston Gregory This is usually expressed in pounds per thousand board feet, a board foot being considered as one-twelfth of a cubic foot.
Sibilance is a manner of articulation of fricative and affricate consonants, made by directing a stream of air with the tongue towards the sharp edge of the teeth, which are held close together; a consonant that uses sibilance may be called a sibilant, or a strident.
SIGINT stands for SIGnals INTelligence, which is intelligence-gathering by interception of signals, whether by radio interception or other means. SIGINT is actually a broad discipline under which multiple sub-disciplines fall. There are three major sub-disciplines that fall under SIGINT which are COMmunications INTelligence (COMINT), ELectronic INTelligence (ELINT), and Foreign Instrumentation Signals INTelligence (FISINT).