Stenosis is primarily a medical word, but one that can be effectively used for other things.
In medical school a sly way to say somebody was stupid was to say he had cerebral stenosis.

stenosis
n.
ModL < Gr stenbsis: see STENO3 & 3OSIS6Med. a narrowing, or constriction, of a passage, duct, opening, etc.
stenotic
adj.