a survival technique, for swimmers or nonswimmers, in which the body is allowed to float vertically in the water, with the head submerged, the lungs filled with air, and the arms and legs relaxed, the head being raised to breathe every ten seconds or so.
a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.
a screen or mat covered with a dark material for shielding a camera lens from excess light or glare.