(typography) the ban on separating multiple successive instances of certain leading punctuation marks, such as multiple successive em dashes, wavy dashes, two-dot leaders, ellipses, etc., during line breaking

(neuroscience) chemotransmitter

separation / segregation / selectivity or sensitivity in a radio or similar device for certain frequencies

to separate / to segregate

prohibition

to ban; to prohibit

chemistry (branch of natural science)

material, substance

chemistry (branch of natural science)

(grammar) separable verb