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.
flutter - the motion made by flapping up and down. flapping, fluttering, flap. undulation, wave - (physics) a movement up and down or back and forth. Verb: 1. flutter - move along rapidly and lightly; skim or dart; The hummingbird flitted among the branches dart, fleet, flit. butterfly - flutter like a butterfly