abbreviation approach astriction astringency asymptote bar barrier blank wall blind alley blind gut block blockade blockage canal catch cecum cervix channel choking choking off circumscription clog coarctation collision course compactedness compaction compression compressure concentralization concentration concourse concurrence condensation confluence conflux congestion congress consolidation constipation constriction constringency contraction contracture convergence converging cordon costiveness crossing cul-de-sac curtailment curtain dead end decrease defile determent deterrent difficulty diminuendo drawback embolism embolus focalization focus funnel gorge hang-up hazard hitch hourglass hourglass figure hub hurdle impasse impediment infarct infarction isthmus jam joker knitting meeting mutual approach narrow narrow place narrowing narrowing gap narrows neck objection obstacle obstipation obstruction obstructive one small difficulty pass puckering pursing radius reduction rub sealing off shortening snag solidification spokes stop stoppage strait stranglement strangulation striction stricture stumbling block stumbling stone systole tangent throat wasp waist wrinkling