18a;P*u*t; Unit of measurement for type sizes and spacing used in printing, publishing & topography.
3d; *o*s; James *o*s; Scottish author who wrote the novel "The private memoirs and Confessions of a Justified Sinner" in 1824.
22d; N*o*l*; Informal term for the human head.
23d; "O*e*a is where a guy gets stabbed in the back and instead of dying he sings." Robert Burns.